API Reference

PNG to JPG Converter

Convert a PNG image to JPG. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/png-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":90}'

{
  "success": true,
  "tool": "png-to-jpg",
  "result": "Binary image data — the Content-Type response header names the output format."
}

JPG to PNG Converter

Convert a JPG image to PNG. Send `file` as binary multipart form-data; there are no other fields.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/jpg-to-png \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "jpg-to-png",
  "result": "Binary image data — the Content-Type response header names the output format."
}

PNG to WEBP Converter

Convert a PNG image to WEBP. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/png-to-webp \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":80}'

{
  "success": true,
  "tool": "png-to-webp",
  "result": "Binary image data — the Content-Type response header names the output format."
}

WEBP to PNG Converter

Convert a WEBP image to PNG. Send `file` as binary multipart form-data; there are no other fields.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/webp-to-png \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "webp-to-png",
  "result": "Binary image data — the Content-Type response header names the output format."
}

JPG to WEBP Converter

Convert a JPG image to WEBP. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/jpg-to-webp \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":80}'

{
  "success": true,
  "tool": "jpg-to-webp",
  "result": "Binary image data — the Content-Type response header names the output format."
}

WEBP to JPG Converter

Convert a WEBP image to JPG. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/webp-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":90}'

{
  "success": true,
  "tool": "webp-to-jpg",
  "result": "Binary image data — the Content-Type response header names the output format."
}

SVG to PNG Converter

Rasterize an SVG image to PNG. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/svg-to-png \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"width":512}'

{
  "success": true,
  "tool": "svg-to-png",
  "result": "Binary image data — the Content-Type response header names the output format."
}

GIF to WEBP Converter

Convert a GIF image to WEBP (first frame only). Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/gif-to-webp \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":80}'

{
  "success": true,
  "tool": "gif-to-webp",
  "result": "Binary image data — the Content-Type response header names the output format."
}

BMP to JPG Converter

Convert an uncompressed 24/32-bit BMP image to JPG. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bmp-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":90}'

{
  "success": true,
  "tool": "bmp-to-jpg",
  "result": "Binary image data — the Content-Type response header names the output format."
}

TIFF to JPG Converter

Convert a TIFF image to JPG. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/tiff-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":90}'

{
  "success": true,
  "tool": "tiff-to-jpg",
  "result": "Binary image data — the Content-Type response header names the output format."
}

HEIC to JPG Converter

Convert a HEIC/HEIF image to JPG. The magic bytes are checked before decoding, so non-HEIC input fails fast with a descriptive error instead of an opaque decoder crash. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/heic-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":90}'

{
  "success": true,
  "tool": "heic-to-jpg",
  "result": "Binary image data — Content-Type: image/jpeg."
}

Image Resizer

Resize an image, keeping its original format (animated GIF: first frame only). BMP input is not supported via the API. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-resizer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"width":800,"height":600,"fit":"inside"}'

{
  "success": true,
  "tool": "image-resizer",
  "result": "Binary image data — the Content-Type response header names the output format."
}

Image Compressor

Compress an image to WEBP. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-compressor \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"quality":70}'

{
  "success": true,
  "tool": "image-compressor",
  "result": "Binary image data — the Content-Type response header names the output format."
}

Image Cropper

Crop an image to a rectangle, keeping its original format (animated GIF: first frame only). BMP input is not supported via the API. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-cropper \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"left":0,"top":0,"width":200,"height":200}'

{
  "success": true,
  "tool": "image-cropper",
  "result": "Binary image data — the Content-Type response header names the output format."
}

Image Rotator

Rotate an image by an arbitrary angle, keeping its original format (animated GIF: first frame only). BMP input is not supported via the API. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-rotator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"angle":90,"background":"#000000"}'

{
  "success": true,
  "tool": "image-rotator",
  "result": "Binary image data — the Content-Type response header names the output format."
}

ICO Converter (Favicon Generator)

Resize an image down to a square favicon size. sharp cannot emit real .ico containers, so this returns a PNG at the chosen size (Content-Type image/png) instead of an ICO file — the legacy UI tool does the same. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ico-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"sizes":"32"}'

{
  "success": true,
  "tool": "ico-converter",
  "result": "Binary image data — the Content-Type response header names the output format."
}

Image to Base64

Encode an image as a base64 string. Send `file` as binary multipart form-data; returns JSON with the encoded data instead of a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-to-base64 \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "image-to-base64",
  "result": {
    "base64": "iVBORw0KGgoAAAANSUhEUgAAAAQAAAAE...",
    "mimeType": "image/png",
    "size": 68
  }
}

Image Watermark Tool

Overlay text on an image as a watermark. Only text watermarks are supported via this API in this batch — image-on-image watermarking remains a UI-only feature for now. Send `file` as binary multipart form-data; the example below shows the other fields only.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-watermark \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"Sample Watermark","fontSize":48,"opacity":0.5,"position":"bottom-right","color":"#ffffff"}'

{
  "success": true,
  "tool": "image-watermark",
  "result": "Binary image data — the Content-Type response header names the output format."
}

Image Metadata Viewer

Return technical image metadata (format, dimensions, color space, and more) as JSON, from sharp's decoder. Deep EXIF tags (camera make/model, GPS, capture time) are only available in the browser-based Image Metadata Viewer UI tool, not via this API. BMP and HEIC input are not supported here — convert to PNG/JPEG/WEBP/GIF/TIFF first. Send `file` as binary multipart form-data.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-metadata-viewer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "image-metadata-viewer",
  "result": {
    "format": "jpeg",
    "width": 800,
    "height": 600,
    "space": "srgb",
    "channels": 3,
    "depth": "uchar",
    "density": 72,
    "hasAlpha": false,
    "hasProfile": false
  }
}

Image Format Detector

Detect an image's true format, dimensions, and MIME type by inspecting its bytes rather than trusting the filename or the Content-Type header. BMP is detected from its header magic bytes without a full pixel decode (sharp has no BMP codec in this build). HEIC is not supported via this API. Send `file` as binary multipart form-data.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-format-detector \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "image-format-detector",
  "result": {
    "format": "png",
    "width": 800,
    "height": 600,
    "mimeType": "image/png"
  }
}

Bulk Image Renamer

Compute a bulk-rename plan for a list of filenames using a pattern with {n} (zero-padded sequence number), {name} (original name without its extension), and {ext} (original extension without the dot) tokens. This endpoint is JSON-only: no files are uploaded and nothing is renamed server-side — the UI applies the returned `to` names when it builds the renamed zip.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bulk-image-renamer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"filenames":"IMG_001.jpg\nIMG_002.png","pattern":"photo-{n}.{ext}","start":1}'

{
  "success": true,
  "tool": "bulk-image-renamer",
  "result": {
    "renames": [
      {
        "from": "IMG_001.jpg",
        "to": "photo-1.jpg"
      },
      {
        "from": "IMG_002.png",
        "to": "photo-2.png"
      }
    ]
  }
}

PDF to DOCX

Convert a PDF to an editable Word .docx document via a headless LibreOffice subprocess, using LibreOffice's Writer PDF-import filter to reflow the PDF into real text (not embedded page images). This runs SERVER-SIDE — the uploaded file is sent to and processed on the server, unlike this site's browser-local client tools. Fidelity depends on the source PDF: a text-based PDF reflows well, a scanned/rasterized PDF will not.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-to-docx \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "pdf-to-docx",
  "result": "Binary DOCX data (Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document) — filename \"converted.docx\"."
}

DOCX to PDF

Convert a Word .docx document to PDF via a headless LibreOffice subprocess (`soffice --convert-to pdf`). This runs SERVER-SIDE for true layout fidelity (fonts, tables, images render the same way LibreOffice/Word itself would lay them out) — unlike this site's browser-local client tools, the uploaded file is sent to and processed on the server.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/docx-to-pdf \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "docx-to-pdf",
  "result": "Binary PDF data (Content-Type: application/pdf) — filename \"converted.pdf\"."
}

PDF Merge

Merge two or more PDF files into one, preserving page order (files are concatenated in the order they are sent). Each upload is checked for the %PDF- signature before any parsing, and the combined page count is capped at 500. Send the PDFs as repeated `files` fields in multipart form-data; returns the merged PDF as a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-merge \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "pdf-merge",
  "result": "Binary PDF data (Content-Type: application/pdf) — the merged document, filename \"merged.pdf\"."
}

PDF Split

Split a PDF into multiple PDFs, returned as a ZIP archive. With no `ranges`, every page becomes its own 1-page PDF (page-1.pdf, page-2.pdf, …). With `ranges` like "1-3,5,8-10", each comma-separated group becomes one PDF (pages-1-3.pdf, page-5.pdf, …). Ranges are 1-based and validated against the page count; a malformed or backwards range is rejected. The source page count is capped at 500. Returns a ZIP (application/zip).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-split \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"ranges":"1-3,5,8-10"}'

{
  "success": true,
  "tool": "pdf-split",
  "result": "Binary ZIP data (Content-Type: application/zip) containing one PDF per range, filename \"split.zip\"."
}

PDF Compress

Re-save a PDF with garbage-collection of unused objects plus stream/image/font recompression (mupdf), returning the optimized PDF. This is a real, structural size reduction, not a lossy "magic" compressor — the gain (if any) depends entirely on the source file; an already-optimized PDF may come back the same size or, rarely, slightly larger. The response carries `x-original-size` and `x-compressed-size` headers (in bytes) alongside the binary body so a caller can see the actual before/after sizes rather than a claimed one.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-compress \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "pdf-compress",
  "result": "Binary PDF data (Content-Type: application/pdf) — filename \"compressed.pdf\", with x-original-size / x-compressed-size response headers (bytes)."
}

PDF to Text

Extract text from a PDF via pdfjs-dist's Node "legacy" build. Omit `page` to concatenate every page's text (pages joined by a blank line); pass a 1-based `page` to extract just that one page. The document is bounded to 500 pages. Returns JSON, not a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-to-text \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "pdf-to-text",
  "result": {
    "text": "Hello, world.",
    "pages": 1,
    "characters": 13
  }
}

CSV to JSON

Parse CSV text into JSON per RFC 4180: quoted fields may contain the delimiter, raw newlines, and `""` as an escaped `"`. With `header:true` (default) the first row becomes object keys and short/long rows are padded/truncated to the header's column count; with `header:false` each row is returned as a plain array.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/csv-to-json \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"csv":"name,age\nAlice,30\nBob,25"}'

{
  "success": true,
  "tool": "csv-to-json",
  "result": {
    "rows": [
      {
        "name": "Alice",
        "age": "30"
      },
      {
        "name": "Bob",
        "age": "25"
      }
    ],
    "count": 2
  }
}

JSON to CSV

Convert a JSON array (of objects, or of arrays) into CSV text. For an array of objects, the column set is the union of every object's keys in first-seen order, and a header row is emitted; missing cells become empty. A field containing the delimiter, a `"`, or a newline is wrapped in quotes with internal `"` doubled.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-to-csv \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"json":"[{\"a\":1,\"b\":2},{\"a\":3,\"b\":4}]"}'

{
  "success": true,
  "tool": "json-to-csv",
  "result": {
    "csv": "a,b\n1,2\n3,4"
  }
}

XML to JSON

Parse XML into JSON via fast-xml-parser (attributes are kept, prefixed "@_"). fast-xml-parser has no DOCTYPE/external-entity resolution at all, so there is no XXE or "billion laughs" entity-expansion vector; input is still bounded to 5MB to cap plain parse work. Malformed XML (e.g. a mismatched closing tag) is validated up front and rejected before parsing.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/xml-to-json \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"xml":"<root a=\"1\"><b>x</b></root>"}'

{
  "success": true,
  "tool": "xml-to-json",
  "result": {
    "json": {
      "root": {
        "@_a": "1",
        "b": "x"
      }
    }
  }
}

YAML to JSON

Parse YAML into JSON via js-yaml's `load()`, which uses only the safe default schema — it does not recognize (and will not execute) unsafe tags like `!!js/function`. Invalid YAML throws a clear error.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/yaml-to-json \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"yaml":"a: 1\nb:\n  - x\n  - y"}'

{
  "success": true,
  "tool": "yaml-to-json",
  "result": {
    "json": {
      "a": 1,
      "b": [
        "x",
        "y"
      ]
    }
  }
}

JSON to YAML

Convert a JSON value into a YAML document via js-yaml's `dump()`.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-to-yaml \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"json":"{\"a\":1}"}'

{
  "success": true,
  "tool": "json-to-yaml",
  "result": {
    "yaml": "a: 1\n"
  }
}

Excel to CSV

Convert one sheet of an Excel workbook (.xlsx or legacy .xls) to CSV, via SheetJS (`xlsx`) — pure JS, runs entirely in this process, no LibreOffice involved. Pass `sheet` as a sheet name, or a 0-based numeric index, to pick a sheet other than the first; the response always lists every sheet name so a caller can target a different one. A sheet with more than 500,000 cells is rejected rather than converted.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/excel-to-csv \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "excel-to-csv",
  "result": {
    "csv": "a,b\n1,2\n3,4",
    "sheet": "Sheet1",
    "sheets": [
      "Sheet1"
    ]
  }
}

Text to PDF

Render plain text into a paginated PDF using Helvetica, word-wrapping to the page width and preserving explicit newlines. Font size and margin are configurable. The produced document is bounded to 500 pages — text that would exceed this is rejected. Returns the PDF as a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-to-pdf \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello, world.\nThis is a PDF generated from text.","fontSize":11,"margin":50}'

{
  "success": true,
  "tool": "text-to-pdf",
  "result": "Binary PDF data (Content-Type: application/pdf) — the rendered document, filename \"document.pdf\"."
}

HTML to PDF

Render an HTML string to PDF via headless Chrome (`page.pdf()`). This runs SERVER-SIDE — the HTML is sent to and rendered on the server, unlike this site's browser-local client tools. For safety, JavaScript execution is disabled and every request the page would make other than a `data:` URL (http/https/file/ftp, including internal hosts and cloud-metadata endpoints) is blocked outright, so external stylesheets, fonts, and images will not load — inline everything (e.g. `data:` URIs) that must appear in the output.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/html-to-pdf \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"html":"<h1>Hello</h1><p>Rendered to PDF.</p>"}'

{
  "success": true,
  "tool": "html-to-pdf",
  "result": "Binary PDF data (Content-Type: application/pdf) — filename \"document.pdf\"."
}

PDF to JPG

Rasterize a PDF to JPEG or PNG images via mupdf. Pass a 1-based `page` to render just that one page (returns a single image); omit it to render every page (returns a ZIP of page-1.jpg, page-2.jpg, …). `dpi` is capped at 300 no matter what value is sent. The document is bounded to 500 pages.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-to-jpg \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"dpi":150,"format":"jpeg"}'

{
  "success": true,
  "tool": "pdf-to-jpg",
  "result": "A single page: binary image data (Content-Type image/jpeg or image/png), filename \"page-{n}.jpg\". Every page (no `page` given): a ZIP archive (Content-Type application/zip), filename \"pages.zip\"."
}

JPG to PDF

Combine one or more JPEG/PNG images into a single PDF, one image per page. Each upload is checked for a PNG or JPEG signature before embedding. With `pageSize:"fit"` (default) each page is exactly the image size; "a4"/"letter" place the image, scaled to fit within an optional margin, on a fixed-size page in the chosen orientation. The image count is capped at 500. Send the images as repeated `files` fields; returns a binary PDF.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/jpg-to-pdf \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"pageSize":"fit","orientation":"portrait","margin":0}'

{
  "success": true,
  "tool": "jpg-to-pdf",
  "result": "Binary PDF data (Content-Type: application/pdf) — one image per page, filename \"images.pdf\"."
}

PDF Page Rotator

Rotate pages of a PDF by 90, 180, or 270 degrees (clockwise). By default every page is rotated; pass `pages` as a 1-based range (e.g. "1-3,5") to rotate only some. The rotation is added to each page's existing rotation. The page count is capped at 500. Returns the rotated PDF as a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-page-rotator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"angle":"90","pages":"1-3,5"}'

{
  "success": true,
  "tool": "pdf-page-rotator",
  "result": "Binary PDF data (Content-Type: application/pdf) — the rotated document, filename \"rotated.pdf\"."
}

PDF Watermark

Stamp a diagonal text watermark across every page of a PDF, drawn as embedded Helvetica-Bold text (this is a text watermark, not HTML). Options control opacity, font size, hex color, and rotation angle. The page count is capped at 500. Returns the watermarked PDF as a binary body.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-watermark \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"CONFIDENTIAL","opacity":0.3,"fontSize":50,"color":"#808080","angle":45}'

{
  "success": true,
  "tool": "pdf-watermark",
  "result": "Binary PDF data (Content-Type: application/pdf) — the watermarked document, filename \"watermarked.pdf\"."
}

PDF Password Protect / Unlock

Add or remove password protection on a PDF via mupdf (AES-256). `mode:"protect"` encrypts it, requiring `password` to open it afterward (`ownerPassword`, if given, separately controls edit/print permissions; it defaults to the same value as `password`). `mode:"unlock"` removes protection given the PDF's correct current password — a wrong or missing password throws a 400, never a corrupted or still-locked file. HONESTY NOTE: this tool runs SERVER-SIDE for both the website and this API — there is no browser-local version. The file and password are sent to the server to perform the operation and are discarded immediately afterward; neither is ever logged or persisted.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pdf-password-protect \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"protect","password":"correct horse battery staple"}'

{
  "success": true,
  "tool": "pdf-password-protect",
  "result": "Binary PDF data (Content-Type: application/pdf) — filename \"protected.pdf\" (\"unlock\" mode: \"unlocked.pdf\")."
}

Markdown to PDF

Render Markdown to PDF: parsed to HTML via `marked`, wrapped in a minimal readable-typography stylesheet, then rendered via headless Chrome exactly like html-to-pdf (same server-side execution, same JavaScript-off and non-`data:`-request-blocking hardening — see that tool's notes). Runs SERVER-SIDE, unlike this site's browser-local client tools.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/markdown-to-pdf \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"markdown":"# Hello\n\nRendered to **PDF**."}'

{
  "success": true,
  "tool": "markdown-to-pdf",
  "result": "Binary PDF data (Content-Type: application/pdf) — filename \"document.pdf\"."
}

Word Counter

Count words, characters, sentences, paragraphs, and estimate reading time.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/word-counter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello world. This is a test."}'

{
  "success": true,
  "tool": "word-counter",
  "result": {
    "words": 6,
    "characters": 28,
    "charactersNoSpaces": 23,
    "sentences": 2,
    "paragraphs": 1,
    "readingTimeMinutes": 1
  }
}

Text Case Converter

Convert text between upper, lower, title, sentence, camel, pascal, snake, and kebab case.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-case-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"hello world","case":"title"}'

{
  "success": true,
  "tool": "text-case-converter",
  "result": {
    "result": "Hello World",
    "case": "title"
  }
}

Lorem Ipsum Generator

Generate placeholder Lorem Ipsum text as paragraphs, sentences, or words.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/lorem-ipsum-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"count":1,"unit":"sentences","startWithLorem":true}'

{
  "success": true,
  "tool": "lorem-ipsum-generator",
  "result": {
    "result": "Lorem ipsum dolor sit amet, consectetur adipiscing elit."
  }
}

Slug Generator

Convert text to a URL-friendly slug: lowercased, accents stripped, non-alphanumeric characters removed, words joined with single hyphens.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/slug-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Hello, World! Café"}'

{
  "success": true,
  "tool": "slug-generator",
  "result": {
    "slug": "hello-world-cafe"
  }
}

Text Diff Checker

Compute a diff between two pieces of text, by line or by word, using an LCS-based algorithm bounded to 5000 combined lines/words across both inputs (same bound as the developer code-diff-tool).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-diff-checker \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"textA":"a\nb","textB":"a\nb\nc","mode":"lines"}'

{
  "success": true,
  "tool": "text-diff-checker",
  "result": {
    "diff": [
      {
        "type": "same",
        "value": "a"
      },
      {
        "type": "same",
        "value": "b"
      },
      {
        "type": "add",
        "value": "c"
      }
    ],
    "additions": 1,
    "deletions": 0
  }
}

Extract Emails

Extract all email addresses found in text.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/extract-emails \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Contact a@example.com or b@example.com, or a@example.com again.","unique":true}'

{
  "success": true,
  "tool": "extract-emails",
  "result": {
    "results": [
      "a@example.com",
      "b@example.com"
    ],
    "count": 2
  }
}

Extract URLs

Extract all http(s) URLs found in text.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/extract-urls \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Visit https://example.com or https://example.com/about.","unique":true}'

{
  "success": true,
  "tool": "extract-urls",
  "result": {
    "results": [
      "https://example.com",
      "https://example.com/about"
    ],
    "count": 2
  }
}

Find and Replace

Find and replace text using literal string matching — `find` is matched exactly, not as a regular expression. Both `find` and `replace` are capped at 10,000 characters and `input` at 100,000. Regex-mode find/replace is available in the browser Find and Replace tool, which runs client-side in the requesting browser rather than on the API server; this API endpoint does not accept a `regex` option.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/find-and-replace \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"The cat sat on the mat","find":"at","replace":"og","caseSensitive":true}'

{
  "success": true,
  "tool": "find-and-replace",
  "result": {
    "result": "The cog sog on the mog",
    "count": 3
  }
}

Reading Time Estimator

Estimate how long it takes to read a piece of text at a given words-per-minute pace.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/reading-time-estimator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word word","wpm":200}'

{
  "success": true,
  "tool": "reading-time-estimator",
  "result": {
    "words": 200,
    "minutes": 1,
    "seconds": 0,
    "text": "~1 min"
  }
}

Duplicate Line Remover

Remove duplicate lines from text, keeping the first occurrence of each.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/duplicate-line-remover \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"a\nA\na\nb","caseSensitive":true,"trimLines":false}'

{
  "success": true,
  "tool": "duplicate-line-remover",
  "result": {
    "result": "a\nA\nb",
    "removed": 1
  }
}

Sort Lines

Sort the lines of text alphabetically (ascending/descending), by length, or into a random order.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/sort-lines \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"banana\napple\ncherry","order":"asc","caseSensitive":true}'

{
  "success": true,
  "tool": "sort-lines",
  "result": {
    "result": "apple\nbanana\ncherry"
  }
}

Text to Binary

Convert text to space-separated 8-bit binary (UTF-8 byte-based, so multi-byte characters round-trip correctly) or decode space/newline-separated 8-bit binary groups back to text.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-to-binary \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Hi","direction":"to-binary"}'

{
  "success": true,
  "tool": "text-to-binary",
  "result": {
    "result": "01001000 01101001"
  }
}

Text Reverser

Reverse text by characters (code-point safe, so emoji/astral characters are not corrupted), by word order, or by line order.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-reverser \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Hello world","mode":"characters"}'

{
  "success": true,
  "tool": "text-reverser",
  "result": {
    "result": "dlrow olleH"
  }
}

Text Repeater

Repeat a string a given number of times, joined by an optional separator. Output size is capped at 1,000,000 characters.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-repeater \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"ab","count":3,"separator":"-"}'

{
  "success": true,
  "tool": "text-repeater",
  "result": {
    "result": "ab-ab-ab"
  }
}

Text Trimmer

Trim whitespace from text. "lines" (default) trims each line individually and keeps blank lines; "all" also collapses repeated internal whitespace and drops blank lines; "leading"/"trailing" trim only one side of the whole text as a single block.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-trimmer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"  hello  \n  world  ","mode":"lines"}'

{
  "success": true,
  "tool": "text-trimmer",
  "result": {
    "result": "hello\nworld"
  }
}

Character Counter

Break text down by character type: total characters, characters excluding whitespace, letters, digits, punctuation, and UTF-8 byte length. Distinct from word-counter, which reports words/sentences/paragraphs/reading time.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/character-counter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Hi 42, world!"}'

{
  "success": true,
  "tool": "character-counter",
  "result": {
    "characters": 13,
    "charactersNoSpaces": 11,
    "letters": 7,
    "digits": 2,
    "punctuation": 2,
    "bytes": 13
  }
}

Text Encryption/Decryption

Apply a classical cipher (caesar, rot13, atbash, base64, or reverse) to text. These are classical ciphers for learning/obfuscation, NOT secure encryption — do not use this to protect real secrets.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-encryption \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"Hello, World!","method":"caesar","shift":3,"mode":"encrypt"}'

{
  "success": true,
  "tool": "text-encryption",
  "result": {
    "result": "Khoor, Zruog!"
  }
}

Whitespace Visualizer

Make whitespace visible: spaces become "·", tabs become "→", and each line ending is marked with "¶".

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/whitespace-visualizer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"a b\tc"}'

{
  "success": true,
  "tool": "whitespace-visualizer",
  "result": {
    "result": "a·b→c"
  }
}

String Escape/Unescape

Escape or unescape text for embedding in JSON, HTML, a URL, or JavaScript source.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/string-escape-unescape \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"<b>hi</b>","format":"html","mode":"escape"}'

{
  "success": true,
  "tool": "string-escape-unescape",
  "result": {
    "result": "&lt;b&gt;hi&lt;/b&gt;"
  }
}

Random Text Generator

Generate cryptographically random text using node:crypto, for tokens/placeholders/test data.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/random-text-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"length":16,"charset":"alphanumeric"}'

{
  "success": true,
  "tool": "random-text-generator",
  "result": {
    "result": "aZ3kQ9mP1xL7vB2c"
  }
}

Text Column Formatter

Align delimited text (e.g. CSV-like rows) into padded columns for readability. Formatted output size is capped at 1,000,000 characters.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/text-column-formatter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"name,age\nAlice,30\nBob,7","delimiter":",","align":"left"}'

{
  "success": true,
  "tool": "text-column-formatter",
  "result": {
    "result": "name , age\nAlice, 30\nBob  , 7"
  }
}

Invisible Character Detector

Detect zero-width and other invisible/formatting Unicode characters in text, and return a cleaned copy with them stripped.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/invisible-character-detector \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"a​b"}'

{
  "success": true,
  "tool": "invisible-character-detector",
  "result": {
    "found": [
      {
        "char": "​",
        "name": "ZERO WIDTH SPACE",
        "position": 1,
        "codePoint": 8203
      }
    ],
    "count": 1,
    "cleaned": "ab"
  }
}

JSON Formatter / Beautifier

Parse and re-serialize JSON with a configurable indent width.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-formatter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"a\":1,\"b\":[2,3]}","indent":2}'

{
  "success": true,
  "tool": "json-formatter",
  "result": {
    "result": "{\n  \"a\": 1,\n  \"b\": [\n    2,\n    3\n  ]\n}"
  }
}

JSON Validator

Check whether a string is valid JSON. This never fails the request for invalid JSON — `valid: false` with a parser error message is the expected response for malformed input.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-validator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"a\":1}"}'

{
  "success": true,
  "tool": "json-validator",
  "result": {
    "valid": true,
    "error": null
  }
}

JSON Minifier

Parse JSON and re-serialize it with all insignificant whitespace removed.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-minifier \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"{\n  \"a\": 1,\n  \"b\": [2, 3]\n}"}'

{
  "success": true,
  "tool": "json-minifier",
  "result": {
    "result": "{\"a\":1,\"b\":[2,3]}"
  }
}

UUID Generator

Generate one or more version-4 (random) UUIDs.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/uuid-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"count":3,"version":"v4"}'

{
  "success": true,
  "tool": "uuid-generator",
  "result": {
    "uuids": [
      "9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d",
      "e3f1c2a0-5e4b-4c7a-9a1f-6d8b2e0f1a2b",
      "2c5ea4c0-4067-11e9-8bad-9b1deb4d3b7d"
    ]
  }
}

JWT Decoder

Decode a JWT’s header and payload segments without verifying its signature. This tool DOES NOT verify the signature, check expiry, or validate the signing key in any way — it only base64url-decodes the header and payload JSON.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/jwt-decoder \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"token":"eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTY3ODkwIn0.dummysignature"}'

{
  "success": true,
  "tool": "jwt-decoder",
  "result": {
    "header": {
      "alg": "HS256"
    },
    "payload": {
      "sub": "1234567890"
    },
    "signaturePresent": true
  }
}

CSS Minifier

Strip comments and insignificant whitespace from CSS.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/css-minifier \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"body {\n  color: red;\n}"}'

{
  "success": true,
  "tool": "css-minifier",
  "result": {
    "result": "body{color:red}"
  }
}

HTML Formatter

Re-indent HTML by breaking tags onto their own lines (regex-based, not a real HTML parser).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/html-formatter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"<div><p>Hi</p></div>"}'

{
  "success": true,
  "tool": "html-formatter",
  "result": {
    "result": "<div><p>Hi\n</p>\n</div>"
  }
}

SQL Formatter

Re-indent a SQL query by placing common keywords on new lines (keyword-based, not a real SQL parser).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/sql-formatter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"select * from users where id = 1"}'

{
  "success": true,
  "tool": "sql-formatter",
  "result": {
    "result": "SELECT *\nFROM users\nWHERE id = 1"
  }
}

Base64 Encode/Decode

Encode UTF-8 text to Base64 or decode a Base64 string back to UTF-8 text. For encoding binary files, use image-to-base64 instead.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/base64-encode-decode \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"hello","mode":"encode"}'

{
  "success": true,
  "tool": "base64-encode-decode",
  "result": {
    "result": "aGVsbG8="
  }
}

URL Encode/Decode

Percent-encode or percent-decode a string for use in a URL.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/url-encode-decode \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"hello world/?","mode":"encode"}'

{
  "success": true,
  "tool": "url-encode-decode",
  "result": {
    "result": "hello%20world%2F%3F"
  }
}

Unix Timestamp Converter

Convert between Unix timestamps (seconds or milliseconds) and human-readable dates.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/unix-timestamp-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":"1700000000","direction":"to-date"}'

{
  "success": true,
  "tool": "unix-timestamp-converter",
  "result": {
    "iso": "2023-11-14T22:13:20.000Z",
    "utc": "Tue, 14 Nov 2023 22:13:20 GMT",
    "unix": 1700000000
  }
}

Cron Expression Explainer

Parse a standard 5-field cron expression (minute hour day-of-month month day-of-week) into a human-readable description, plus the common @yearly/@annually/@monthly/@weekly/@daily/@midnight/@hourly aliases. 6- and 7-field expressions (seconds/year) are not supported.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/cron-expression-explainer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"expression":"0 9 * * 1-5"}'

{
  "success": true,
  "tool": "cron-expression-explainer",
  "result": {
    "description": "At 09:00, Monday through Friday.",
    "fields": {
      "minute": "at minute 0",
      "hour": "at hour 9",
      "dayOfMonth": "every day of the month",
      "month": "every month",
      "dayOfWeek": "Monday through Friday"
    }
  }
}

JavaScript Minifier

Strip comments and insignificant whitespace from JavaScript using regex-based rules (not a real parser — template literals and regex literals containing `//` or braces are not specially handled).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/javascript-minifier \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"function add(a, b) {\n  return a + b;\n}"}'

{
  "success": true,
  "tool": "javascript-minifier",
  "result": {
    "result": "function add(a,b){return a+b;}"
  }
}

HTML Entity Encoder

Encode special characters as HTML entities, or decode HTML entities back to characters. Decoding only resolves character entities (numeric and a common named set) — it does not parse or execute HTML.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/html-entity-encoder \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"<a href=\"x\">A & B</a>"}'

{
  "success": true,
  "tool": "html-entity-encoder",
  "result": {
    "result": "&lt;a href=&quot;x&quot;&gt;A &amp; B&lt;/a&gt;"
  }
}

Markdown to HTML

Render Markdown to HTML using the site’s basic Markdown subset (headers, bold/italic, links, images, lists, blockquotes, code blocks/inline code, horizontal rules, paragraphs) — not a full CommonMark implementation.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/markdown-to-html \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"markdown":"# Hello\n\nThis is **bold** text."}'

{
  "success": true,
  "tool": "markdown-to-html",
  "result": {
    "html": "<h2 style=\"margin-top: 2rem; margin-bottom: 1rem;\">Hello</h2><p style=\"margin-bottom: 1rem;\">This is <strong>bold</strong> text.</p>"
  }
}

Code Diff Tool

Compute a line-by-line diff between two text/code snippets using an LCS-based algorithm, bounded to 5000 combined lines across both inputs.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/code-diff-tool \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"textA":"line1\nline2","textB":"line1\nline2\nline3"}'

{
  "success": true,
  "tool": "code-diff-tool",
  "result": {
    "diff": [
      {
        "type": "same",
        "line": "line1"
      },
      {
        "type": "same",
        "line": "line2"
      },
      {
        "type": "add",
        "line": "line3"
      }
    ],
    "additions": 1,
    "deletions": 0
  }
}

JSON to TypeScript Interface Generator

Generate a TypeScript interface (or a type alias for array/primitive roots) from a JSON value, producing union types for mixed-primitive arrays and inline nested object types.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-to-typescript \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"id\":1,\"name\":\"Widget\"}","rootName":"Root"}'

{
  "success": true,
  "tool": "json-to-typescript",
  "result": {
    "typescript": "interface Root {\n  id: number;\n  name: string;\n}"
  }
}

JSON Path Finder

Parse JSON and list the JSONPath expression for every leaf value (and every empty object/array).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/json-path-finder \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"{\"a\":1,\"b\":[2,3]}"}'

{
  "success": true,
  "tool": "json-path-finder",
  "result": {
    "paths": [
      "$.a",
      "$.b[0]",
      "$.b[1]"
    ]
  }
}

CSS Gradient Generator

Generate a CSS linear-gradient() or radial-gradient() value from 2-10 hex colors.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/css-gradient-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"type":"linear","angle":90,"colors":"#ff0000,#0000ff"}'

{
  "success": true,
  "tool": "css-gradient-generator",
  "result": {
    "css": "linear-gradient(90deg, #ff0000, #0000ff)"
  }
}

SVG Optimizer

Strip comments, redundant whitespace, xmlns: namespaces, data- attributes, and id attributes from an SVG document (regex-based, not a full XML optimizer).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/svg-optimizer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"<svg xmlns=\"http://www.w3.org/2000/svg\">\n  <rect id=\"a\" width=\"10\" height=\"10\" />\n</svg>"}'

{
  "success": true,
  "tool": "svg-optimizer",
  "result": {
    "result": "<svg xmlns=\"http://www.w3.org/2000/svg\"><rect width=\"10\" height=\"10\"/></svg>"
  }
}

.htaccess Generator

Generate a fixed best-practices .htaccess template (HTTPS redirect, trailing-slash removal, custom error pages, gzip compression, and cache headers). The output does not vary by input.

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/htaccess-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{}'

{
  "success": true,
  "tool": "htaccess-generator",
  "result": {
    "result": "# .htaccess Generated by FreeConvertingTools\n\n# Enable Rewrite Engine\nRewriteEngine On\n\n# Force HTTPS\nRewriteCond %{HTTPS} off\nRewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]\n\n# Remove trailing slash\nRewriteCond %{REQUEST_FILENAME} !-d\nRewriteRule ^(.*)/$ /$1 [L,R=301]\n\n# Custom error pages\nErrorDocument 404 /404.html\nErrorDocument 500 /500.html\n\n# Enable compression\n<IfModule mod_deflate.c>\n  AddOutputFilterByType DEFLATE text/html text/plain text/css application/javascript application/json\n</IfModule>\n\n# Cache control\n<IfModule mod_expires.c>\n  ExpiresActive On\n  ExpiresByType image/jpg \"access plus 1 year\"\n  ExpiresByType image/png \"access plus 1 year\"\n  ExpiresByType text/css \"access plus 1 month\"\n  ExpiresByType application/javascript \"access plus 1 month\"\n</IfModule>\n"
  }
}

Robots.txt Generator

Generate a robots.txt with a sensible default allow/disallow policy and a Sitemap line for the given domain.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/robots-txt-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"domain":"https://example.com"}'

{
  "success": true,
  "tool": "robots-txt-generator",
  "result": {
    "result": "# robots.txt Generated by FreeConvertingTools\n# https://example.com\n\nUser-agent: *\nAllow: /\n\n# Disallow admin and private paths\nDisallow: /admin/\nDisallow: /api/\nDisallow: /dashboard/\nDisallow: /account/\n\n# Allow search engines to index tool pages\nAllow: /tools/\nAllow: /categories/\nAllow: /blog/\n\n# Sitemap\nSitemap: https://example.com/sitemap.xml\n\n# Crawl delay (in seconds)\nCrawl-delay: 1\n"
  }
}

Sitemap XML Generator

Generate a sitemap.xml document from a newline-separated list of absolute http/https URLs (up to 1000).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/sitemap-xml-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"urls":"https://example.com\nhttps://example.com/about"}'

{
  "success": true,
  "tool": "sitemap-xml-generator",
  "result": {
    "result": "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<urlset ...>...</urlset>"
  }
}

QR Code Generator

Generate a QR code as an <svg> string via the qrcode npm package (never a deprecated third-party image API).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/qr-code-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"data":"https://example.com","size":256,"ecc":"M"}'

{
  "success": true,
  "tool": "qr-code-generator",
  "result": {
    "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"256\" height=\"256\" viewBox=\"0 0 33 33\" shape-rendering=\"crispEdges\"><path fill=\"#ffffff\" d=\"M0 0h33v33H0z\"/><path stroke=\"#000000\" d=\"M4 4.5h7m4 0h3m2 0h1m1 0h7M4 5.5h1m5 0h1m3 0h1m2 0h4m1 0h1m5 0h1M4 6.5h1m1 0h3m1 0h1m1 0h2m1 0h1m2 0h1m3 0h1m1 0h3m1 0h1M4 7.5h1m1 0h3m1 0h1m1 0h1m4 0h3m2 0h1m1 0h3m1 0h1M4 8.5h1m1 0h3m1 0h1m1 0h3m2 0h1m2 0h1m1 0h1m1 0h3m1 0h1M4 9.5h1m5 0h1m1 0h1m2 0h1m2 0h2m2 0h1m5 0h1M4 10.5h7m1 0h1m1 0h1m1 0h1m1 0h1m1 0h1m1 0h7M12 11.5h1m5 0h1m1 0h1M4 12.5h1m1 0h5m5 0h1m5 0h5M5 13.5h1m2 0h2m2 0h1m1 0h2m1 0h1m3 0h1m1 0h1m3 0h1M4 14.5h5m1 0h1m1 0h2m3 0h4m2 0h1m1 0h1m1 0h2M4 15.5h2m1 0h3m2 0h1m1 0h2m1 0h1m1 0h2m1 0h2m4 0h1M5 16.5h3m2 0h1m4 0h2m1 0h2m1 0h2m1 0h1m1 0h3M4 17.5h5m3 0h1m1 0h1m5 0h1m2 0h1m1 0h1m1 0h1M4 18.5h1m5 0h2m2 0h3m2 0h1m2 0h4m1 0h2M4 19.5h1m2 0h1m3 0h1m3 0h1m2 0h7m3 0h1M4 20.5h1m1 0h1m2 0h2m1 0h4m4 0h5m1 0h1M12 21.5h2m2 0h5m3 0h2M4 22.5h7m6 0h2m1 0h1m1 0h1m1 0h1m1 0h3M4 23.5h1m5 0h1m1 0h2m2 0h2m2 0h1m3 0h2m1 0h1M4 24.5h1m1 0h3m1 0h1m1 0h3m1 0h1m1 0h7m1 0h1m1 0h1M4 25.5h1m1 0h3m1 0h1m1 0h1m6 0h1m1 0h2m1 0h5M4 26.5h1m1 0h3m1 0h1m1 0h5m2 0h1m5 0h2m1 0h1M4 27.5h1m5 0h1m4 0h1m2 0h1m1 0h2m1 0h3m2 0h1M4 28.5h7m1 0h2m1 0h1m5 0h8\"/></svg>\n"
  }
}

Barcode Generator

Generate a Code 128 (Subset B) barcode as an <svg> string via a hand-built encoder (start code, mod-103 checksum, stop pattern) — no external dependency.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/barcode-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":"TEST123","format":"code128"}'

{
  "success": true,
  "tool": "barcode-generator",
  "result": {
    "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"264\" height=\"120\" viewBox=\"0 0 264 120\"><rect width=\"264\" height=\"120\" fill=\"#ffffff\"/><rect x=\"20\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"26\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"32\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"42\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"48\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"60\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"64\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"72\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"78\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"86\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"92\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"100\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"108\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"114\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"126\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"130\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"136\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"146\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"152\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"160\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"170\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"174\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"182\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"186\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"196\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"200\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"208\" y=\"10\" width=\"8\" height=\"100\" fill=\"#000000\"/><rect x=\"218\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/><rect x=\"228\" y=\"10\" width=\"6\" height=\"100\" fill=\"#000000\"/><rect x=\"236\" y=\"10\" width=\"2\" height=\"100\" fill=\"#000000\"/><rect x=\"240\" y=\"10\" width=\"4\" height=\"100\" fill=\"#000000\"/></svg>"
  }
}

Password Generator

Generate a cryptographically random password (node:crypto, never Math.random) that is guaranteed to include at least one character from every selected character type.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/password-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"length":16,"includeUppercase":true,"includeLowercase":true,"includeNumbers":true,"includeSymbols":true}'

{
  "success": true,
  "tool": "password-generator",
  "result": {
    "password": "aB3!kQ9mP1xL7vB2"
  }
}

Hash Generator

Compute a hex-encoded cryptographic hash digest of the given text using node:crypto. MD5 and SHA-1 are provided for compatibility/checksums only — neither is safe for password storage or security-sensitive integrity checks.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/hash-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"input":"hello","algorithm":"sha256"}'

{
  "success": true,
  "tool": "hash-generator",
  "result": {
    "hash": "2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824",
    "algorithm": "sha256"
  }
}

Password Strength Checker

Estimate password strength via a length + character-set + common-pattern heuristic (no external dependency, no zxcvbn). NOTE: unlike the browser tool, this API endpoint receives the password over the wire to score it server-side — it is never logged or stored, but it is transmitted, which the browser version avoids.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/password-strength-checker \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"password":"Tr0ub4dor&3"}'

{
  "success": true,
  "tool": "password-strength-checker",
  "result": {
    "score": 3,
    "label": "Strong",
    "entropyBits": 72.1,
    "suggestions": [
      "Use at least 12 characters."
    ]
  }
}

Random Number Generator

Generate one or more random numbers in [min, max] using node:crypto (never Math.random).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/random-number-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"min":1,"max":100,"count":5,"integer":true,"unique":true}'

{
  "success": true,
  "tool": "random-number-generator",
  "result": {
    "numbers": [
      7,
      42,
      13,
      91,
      56
    ]
  }
}

Random Name Generator

Generate random full/first/last names from seed name lists using node:crypto.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/random-name-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"type":"full","gender":"any","count":3}'

{
  "success": true,
  "tool": "random-name-generator",
  "result": {
    "names": [
      "James Smith",
      "Mary Johnson",
      "Robert Williams"
    ]
  }
}

Random Color Generator

Generate random colors in hex, rgb(), or hsl() format using node:crypto.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/random-color-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"format":"hex","count":3}'

{
  "success": true,
  "tool": "random-color-generator",
  "result": {
    "colors": [
      "#a3f2c1",
      "#004488",
      "#ff00aa"
    ]
  }
}

Placeholder Image Generator

Generate a placeholder <svg> image of the requested dimensions with a solid background and centered label text (escaped).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/placeholder-image-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"width":800,"height":600}'

{
  "success": true,
  "tool": "placeholder-image-generator",
  "result": {
    "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"800\" height=\"600\" viewBox=\"0 0 800 600\"><rect width=\"800\" height=\"600\" fill=\"#e5e7eb\"/><text x=\"400\" y=\"300\" font-family=\"sans-serif\" font-size=\"75\" fill=\"#6b7280\" text-anchor=\"middle\" dominant-baseline=\"middle\">800x600</text></svg>"
  }
}

Fake Data Generator

Generate realistic-looking fake data (name, email, address, phone, company, username, lorem text, or date) from seed lists + node:crypto — never real personal data. (A separate uuid-generator endpoint already covers UUIDs.)

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/fake-data-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"type":"email","count":3}'

{
  "success": true,
  "tool": "fake-data-generator",
  "result": {
    "data": [
      "john.smith42@example.com",
      "mary.johnson7@test.org",
      "robert.williams88@mail.com"
    ]
  }
}

Meta Tag Generator

Generate an HTML <meta> tag block (title, description, keywords, author, Open Graph image, Twitter Card) for SEO. Every value is HTML-escaped before being interpolated, so quotes/angle brackets in the input cannot break out of an attribute or inject markup.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/meta-tag-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"title":"My Page","description":"A great page.","keywords":"a, b, c","author":"Jane Doe","ogImage":"https://example.com/image.png","twitterCard":"summary"}'

{
  "success": true,
  "tool": "meta-tag-generator",
  "result": {
    "html": "<title>My Page</title>\n<meta name=\"description\" content=\"A great page.\">\n<meta name=\"keywords\" content=\"a, b, c\">\n<meta name=\"author\" content=\"Jane Doe\">\n<meta property=\"og:title\" content=\"My Page\">\n<meta property=\"og:description\" content=\"A great page.\">\n<meta property=\"og:image\" content=\"https://example.com/image.png\">\n<meta name=\"twitter:card\" content=\"summary\">\n<meta name=\"twitter:title\" content=\"My Page\">\n<meta name=\"twitter:description\" content=\"A great page.\">"
  }
}

Open Graph Tag Generator

Generate Open Graph + Twitter Card <meta> tags for social sharing previews. Every value is HTML-escaped before being interpolated, so quotes/angle brackets in the input cannot break out of an attribute or inject markup.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/open-graph-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"ogTitle":"My Page","ogDescription":"A great page.","ogUrl":"https://example.com","ogType":"website"}'

{
  "success": true,
  "tool": "open-graph-generator",
  "result": {
    "html": "<meta property=\"og:title\" content=\"My Page\">\n<meta property=\"og:description\" content=\"A great page.\">\n<meta property=\"og:type\" content=\"website\">\n<meta property=\"og:url\" content=\"https://example.com\">\n<meta name=\"twitter:card\" content=\"summary\">\n<meta name=\"twitter:title\" content=\"My Page\">\n<meta name=\"twitter:description\" content=\"A great page.\">"
  }
}

Schema Markup Generator

Generate JSON-LD structured data for a schema.org type (Article, Product, Organization, LocalBusiness, FAQPage, BreadcrumbList, Person, Event). The output is built as a plain object and serialized with JSON.stringify — never hand-concatenated — and every literal `<` is then escaped so a field value containing `</script>` cannot terminate the `<script type="application/ld+json">` tag this output is meant to be pasted into.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/schema-markup-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"type":"Article","name":"My Blog Post","author":"Jane Doe","datePublished":"2026-01-01","description":"A great post."}'

{
  "success": true,
  "tool": "schema-markup-generator",
  "result": {
    "jsonld": "{\n  \"@context\": \"https://schema.org\",\n  \"@type\": \"Article\",\n  \"headline\": \"My Blog Post\",\n  \"description\": \"A great post.\",\n  \"author\": {\n    \"@type\": \"Person\",\n    \"name\": \"Jane Doe\"\n  },\n  \"datePublished\": \"2026-01-01\"\n}"
  }
}

Favicon Generator (from Text)

Generate a simple <svg> favicon: a colored square/circle/rounded-square shape with up to 4 characters of centered text (escaped).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/favicon-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"text":"F","bgColor":"4f46e5","textColor":"ffffff","shape":"circle"}'

{
  "success": true,
  "tool": "favicon-generator",
  "result": {
    "svg": "<svg xmlns=\"http://www.w3.org/2000/svg\" width=\"64\" height=\"64\" viewBox=\"0 0 64 64\"><circle cx=\"32\" cy=\"32\" r=\"32\" fill=\"#4f46e5\"/><text x=\"32\" y=\"32\" font-family=\"sans-serif\" font-size=\"32\" font-weight=\"700\" fill=\"#ffffff\" text-anchor=\"middle\" dominant-baseline=\"central\">F</text></svg>"
  }
}

Color Converter

Convert a hex color to its RGB, HSL, HSV, and CMYK equivalents.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/color-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"color":"#FF0000"}'

{
  "success": true,
  "tool": "color-converter",
  "result": {
    "hex": "#FF0000",
    "rgb": {
      "r": 255,
      "g": 0,
      "b": 0
    },
    "hsl": {
      "h": 0,
      "s": 100,
      "l": 50
    },
    "hsv": {
      "h": 0,
      "s": 100,
      "v": 100
    },
    "cmyk": {
      "c": 0,
      "m": 100,
      "y": 100,
      "k": 0
    }
  }
}

Color Palette Generator

Generate a color palette from a base hex color using HSL hue rotation. `scheme` selects the relationship: "complementary" (2 colors, +180°), "triadic" (3, +120°/+240°), "tetradic" (4, +90°/+180°/+270°), "split-complementary" (3, +150°/+210°), "analogous" (`count` colors, 30° steps centered on the base hue), or "monochromatic" (`count` colors, same hue/saturation with varying lightness).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/color-palette-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"color":"#FF0000","scheme":"complementary"}'

{
  "success": true,
  "tool": "color-palette-generator",
  "result": {
    "colors": [
      "#FF0000",
      "#00FFFF"
    ]
  }
}

Contrast Checker (WCAG)

Compute the WCAG 2.x contrast ratio between a foreground and background hex color, using the exact sRGB-linearized relative-luminance formula (not a naive RGB average), and report AA/AAA pass/fail for normal and large text.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/contrast-checker \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"foreground":"#000000","background":"#FFFFFF"}'

{
  "success": true,
  "tool": "contrast-checker",
  "result": {
    "ratio": 21,
    "aa": true,
    "aaLarge": true,
    "aaa": true,
    "aaaLarge": true
  }
}

CSS Gradient Generator

Build a CSS linear-gradient() or radial-gradient() string from 2-10 comma-separated hex colors. `angle` applies only to the "linear" type.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/css-gradient-generator-color \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"type":"linear","angle":90,"colors":"#ff0000,#0000ff"}'

{
  "success": true,
  "tool": "css-gradient-generator-color",
  "result": {
    "css": "linear-gradient(90deg, #FF0000, #0000FF)"
  }
}

Color Blindness Simulator

Simulate how a hex color appears under color vision deficiency (CVD). Protanopia/deuteranopia/tritanopia use the widely-cited simplified RGB-space transformation matrices for dichromacy simulation (as used by common browser-based CVD simulators), applied directly to sRGB channel values without linearizing gamma first. Achromatopsia converts to full grayscale using the Rec. 709 luma formula (0.2126R + 0.7152G + 0.0722B) applied directly to sRGB values — a different, unrelated formula from the WCAG relative-luminance formula contrast-checker uses (that one linearizes each channel first). The "-anomaly" variants (protanomaly/deuteranomaly/tritanomaly) are not separately modeled; as a documented approximation, they blend the corresponding full-dichromacy simulated color 50/50 with the original.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/color-blindness-simulator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"color":"#FF0000","type":"achromatopsia"}'

{
  "success": true,
  "tool": "color-blindness-simulator",
  "result": {
    "original": "#FF0000",
    "simulated": "#363636",
    "type": "achromatopsia"
  }
}

Color Shade/Tint Generator

Generate shades (the base color mixed toward black) and tints (mixed toward white) of a hex color, in RGB space, evenly spaced from near the base color to near black/white.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/color-shade-tint-generator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"color":"#FF0000","steps":3}'

{
  "success": true,
  "tool": "color-shade-tint-generator",
  "result": {
    "shades": [
      "#BF0000",
      "#800000",
      "#400000"
    ],
    "tints": [
      "#FF4040",
      "#FF8080",
      "#FFBFBF"
    ]
  }
}

Image Color Extractor

Extract the top dominant colors from an uploaded image. The image is downsampled to at most 100x10016 and counted; the most frequent quantized colors are returned with their share of the (downsampled) image. Send `file` as binary multipart form-data.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/image-color-extractor \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"count":6}'

{
  "success": true,
  "tool": "image-color-extractor",
  "result": {
    "colors": [
      {
        "hex": "#FF0000",
        "rgb": {
          "r": 255,
          "g": 0,
          "b": 0
        },
        "percentage": 100
      }
    ]
  }
}

Tailwind CSS Color Finder

Find the nearest color(s) in the real Tailwind CSS v3 default palette (22 hues x 11 shades, 50-950) to a given hex color, by Euclidean distance in RGB space (not Lab).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/tailwind-color-finder \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"color":"#ef4444"}'

{
  "success": true,
  "tool": "tailwind-color-finder",
  "result": {
    "input": "#EF4444",
    "name": "red-500",
    "hex": "#EF4444",
    "distance": 0,
    "alternatives": [
      {
        "name": "rose-500",
        "hex": "#F43F5E",
        "distance": 26.94
      },
      {
        "name": "rose-600",
        "hex": "#E11D48",
        "distance": 41.63
      },
      {
        "name": "red-600",
        "hex": "#DC2626",
        "distance": 46.49
      },
      {
        "name": "orange-600",
        "hex": "#EA580C",
        "distance": 59.67
      }
    ]
  }
}

Percentage Calculator

Answer one of three common percentage questions, selected by `mode`: "percent-of" (what is x% of y), "what-percent" (x is what % of y), or "percent-change" (percentage change from x to y).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/percentage-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"percent-of","x":20,"y":150}'

{
  "success": true,
  "tool": "percentage-calculator",
  "result": {
    "percent": 20,
    "of": 150,
    "result": 30
  }
}

Age Calculator

Compute age (years, months, days, and total days) as of a given date (defaults to now).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/age-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"birthDate":"2000-01-01","asOfDate":"2024-06-15"}'

{
  "success": true,
  "tool": "age-calculator",
  "result": {
    "years": 24,
    "months": 5,
    "days": 14,
    "totalDays": 8932
  }
}

Tip Calculator

Calculate a tip amount, total bill, and per-person split.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/tip-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"bill":85.5,"tipPercent":18,"people":4}'

{
  "success": true,
  "tool": "tip-calculator",
  "result": {
    "tipAmount": 15.39,
    "total": 100.89,
    "perPerson": 25.2225
  }
}

Discount Calculator

Calculate the discount amount and final price after applying a percentage discount.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/discount-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"price":99.99,"discountPercent":25}'

{
  "success": true,
  "tool": "discount-calculator",
  "result": {
    "discountAmount": 25,
    "finalPrice": 74.99,
    "saved": 25
  }
}

Roman Numeral Converter

Convert between integers and Roman numerals (1–3999). "to-roman": `value` is a decimal integer string. "from-roman": `value` is a canonical (subtractive-notation) Roman numeral string.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/roman-numeral-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"to-roman","value":"1994"}'

{
  "success": true,
  "tool": "roman-numeral-converter",
  "result": {
    "value": 1994,
    "roman": "MCMXCIV"
  }
}

Number Base Converter

Convert a number (as a string) from one base to another (bases 2–36), using arbitrary-precision arithmetic.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/number-base-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":"ff","fromBase":16,"toBase":10}'

{
  "success": true,
  "tool": "number-base-converter",
  "result": {
    "result": "255"
  }
}

Number to Words

Convert an integer (magnitude up to 1,000,000,000,000,000, i.e. 10^15) into English words.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/number-to-words \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":1994}'

{
  "success": true,
  "tool": "number-to-words",
  "result": {
    "words": "one thousand nine hundred ninety-four"
  }
}

Aspect Ratio Calculator

Simplify width×height to an aspect ratio ("ratio" mode), or solve for a missing dimension given a target ratio and the other dimension ("solve-width"/"solve-height" modes).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/aspect-ratio-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"ratio","width":1920,"height":1080}'

{
  "success": true,
  "tool": "aspect-ratio-calculator",
  "result": {
    "ratioWidth": 16,
    "ratioHeight": 9,
    "decimal": 1.7778
  }
}

Date Difference Calculator

Compute the difference between two dates: total days, weeks, and a calendar-aware years/months/days breakdown.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/date-difference-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"date1":"2024-01-01","date2":"2024-01-08"}'

{
  "success": true,
  "tool": "date-difference-calculator",
  "result": {
    "totalDays": 7,
    "weeks": 1,
    "years": 0,
    "months": 0,
    "days": 7
  }
}

Fraction Calculator

Add, subtract, multiply, or divide two fractions and return the simplified result.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/fraction-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"n1":1,"d1":2,"n2":1,"d2":3,"operation":"add"}'

{
  "success": true,
  "tool": "fraction-calculator",
  "result": {
    "numerator": 5,
    "denominator": 6,
    "decimal": 0.8333333333333334
  }
}

Standard Deviation Calculator

Compute the standard deviation, variance, mean, and count of a dataset (up to 10,000 numbers). `type` selects population (divide by n) or sample (divide by n-1, default) variance.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/standard-deviation-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"numbers":"2,4,4,4,5,5,7,9","type":"population"}'

{
  "success": true,
  "tool": "standard-deviation-calculator",
  "result": {
    "stdDev": 2,
    "variance": 4,
    "mean": 5,
    "count": 8
  }
}

Probability Calculator

Compute a probability, selected by `mode`: "single" (favorable/total outcomes of one event), or "combined" (AND/OR of two independent probabilities, each 0-1, via `operator`).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/probability-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"single","favorable":1,"total":6}'

{
  "success": true,
  "tool": "probability-calculator",
  "result": {
    "probability": 0.16666666666666666,
    "percentage": 16.666666666666664
  }
}

Permutation & Combination Calculator

Compute the number of permutations (nPr) and combinations (nCr) of r items from a set of n (n, r up to 1000).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/permutation-combination-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"n":5,"r":3}'

{
  "success": true,
  "tool": "permutation-combination-calculator",
  "result": {
    "permutations": 60,
    "combinations": 10
  }
}

Matrix Calculator

Perform matrix operations (add, subtract, multiply, determinant, transpose) on one or two matrices, each up to 10x10. Matrices are rows of numbers, one row per line, values space- or comma-separated. `matrixB` is required for add/subtract/multiply.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/matrix-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"matrixA":"1 2\n3 4","matrixB":"5 6\n7 8","operation":"add"}'

{
  "success": true,
  "tool": "matrix-calculator",
  "result": {
    "result": [
      [
        6,
        8
      ],
      [
        10,
        12
      ]
    ],
    "rows": 2,
    "cols": 2
  }
}

Quadratic Equation Solver

Solve ax^2 + bx + c = 0 for x, returning the discriminant, root(s), and their nature (real or complex).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/quadratic-equation-solver \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"a":1,"b":-5,"c":6}'

{
  "success": true,
  "tool": "quadratic-equation-solver",
  "result": {
    "discriminant": 1,
    "roots": [
      3,
      2
    ],
    "nature": "two-real-roots"
  }
}

GPA Calculator

Compute GPA on the standard 4.0 scale from a list of courses (up to 1,000), one "grade credits" pair per line (e.g. "A- 3").

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/gpa-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"courses":"A 3\nB+ 4\nA- 3"}'

{
  "success": true,
  "tool": "gpa-calculator",
  "result": {
    "gpa": 3.63,
    "totalCredits": 10
  }
}

Grade Calculator

Compute a weighted grade from a list of score/weight pairs (up to 1,000), one "score weight" pair per line (e.g. "85 30" for an 85% score weighted at 30%).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/grade-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"items":"85 30\n90 40\n95 30"}'

{
  "success": true,
  "tool": "grade-calculator",
  "result": {
    "grade": 90,
    "totalWeight": 100
  }
}

Mean, Median, Mode Calculator

Compute the mean, median, mode(s), and range of a dataset (up to 10,000 numbers).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/mean-median-mode-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"numbers":"1,2,2,3,4"}'

{
  "success": true,
  "tool": "mean-median-mode-calculator",
  "result": {
    "mean": 2.4,
    "median": 2,
    "mode": [
      2
    ],
    "range": 3,
    "count": 5
  }
}

Ratio Calculator

Simplify a ratio a:b to lowest terms ("simplify" mode), or solve a:b = c:x for the missing fourth term ("solve" mode).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ratio-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"simplify","a":8,"b":12}'

{
  "success": true,
  "tool": "ratio-calculator",
  "result": {
    "simplified": "2:3",
    "ratioA": 2,
    "ratioB": 3
  }
}

Exponent Calculator

Calculate base raised to the power of exponent.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/exponent-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"base":2,"exponent":10}'

{
  "success": true,
  "tool": "exponent-calculator",
  "result": {
    "result": 1024
  }
}

Logarithm Calculator

Calculate the logarithm of a positive value in a given positive base (base ≠ 1). Defaults to base 10.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/logarithm-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":100,"base":10}'

{
  "success": true,
  "tool": "logarithm-calculator",
  "result": {
    "result": 2
  }
}

Prime Factorization Calculator

Compute the prime factorization of an integer >= 2, up to 1,000,000,000, via trial division.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/prime-factorization-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":360}'

{
  "success": true,
  "tool": "prime-factorization-calculator",
  "result": {
    "factors": [
      {
        "prime": 2,
        "exponent": 3
      },
      {
        "prime": 3,
        "exponent": 2
      },
      {
        "prime": 5,
        "exponent": 1
      }
    ],
    "factorization": "2^3 × 3^2 × 5"
  }
}

LCM & GCD Calculator

Compute the GCD (greatest common divisor) and LCM (least common multiple) of a list of integers (up to 100, each with magnitude up to Number.MAX_SAFE_INTEGER = 9007199254740991).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/lcm-gcd-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"numbers":"12, 18, 24"}'

{
  "success": true,
  "tool": "lcm-gcd-calculator",
  "result": {
    "lcm": 72,
    "gcd": 6
  }
}

Binary Calculator

Perform arithmetic or bitwise operations on two binary numbers (up to 20 bits each). A negative result (from subtract) is returned with a leading "-".

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/binary-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"a":"1010","b":"1100","operation":"add"}'

{
  "success": true,
  "tool": "binary-calculator",
  "result": {
    "binary": "10110",
    "decimal": 22
  }
}

Hex Calculator

Perform arithmetic or bitwise operations on two hexadecimal numbers (up to 6 digits each). A negative result (from subtract) is returned with a leading "-".

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/hex-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"a":"FF","b":"1","operation":"add"}'

{
  "success": true,
  "tool": "hex-calculator",
  "result": {
    "hex": "100",
    "decimal": 256
  }
}

BMI Calculator

Calculate Body Mass Index (BMI = weight kg / height m squared) and its standard WHO category. BMI is a population-level screening estimate that does not distinguish muscle from fat — informational and educational only, not medical advice; consult a qualified professional for individual assessment.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bmi-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":70,"height_cm":175}'

{
  "success": true,
  "tool": "bmi-calculator",
  "result": {
    "bmi": 22.86,
    "category": "Normal weight",
    "healthyRangeKg": {
      "min": 56.7,
      "max": 76.3
    }
  }
}

BMR Calculator

Estimate Basal Metabolic Rate (BMR) — the calories your body burns at rest — using the Mifflin-St Jeor equation (default) or the revised Harris-Benedict equation. Informational estimate only, not medical advice; actual metabolic rate varies by individual — consult a qualified healthcare or nutrition professional for personalized guidance.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bmr-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":80,"height_cm":180,"age":30,"sex":"male","formula":"mifflin"}'

{
  "success": true,
  "tool": "bmr-calculator",
  "result": {
    "bmr": 1780,
    "formula": "mifflin",
    "sex": "male"
  }
}

Body Fat Calculator

Estimate body fat percentage using the U.S. Navy circumference method (men: height, neck, waist; women: height, neck, waist, hip). A population-level estimate with a known error margin, not a clinical body-composition measurement (e.g. a DEXA scan) — informational only, not medical advice.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/body-fat-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"sex":"male","height_cm":180,"neck_cm":38,"waist_cm":85}'

{
  "success": true,
  "tool": "body-fat-calculator",
  "result": {
    "sex": "male",
    "method": "US Navy circumference method",
    "bodyFatPercent": 16.1
  }
}

Water Intake Calculator

Estimate daily water intake using the commonly-cited ~35 mL per kilogram of body weight guideline, plus an adjustment of ~12 mL per minute of exercise (roughly 350 mL per 30 minutes). Informational estimate only, not medical advice — actual hydration needs vary with climate, health conditions, and diet.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/water-intake-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":70,"activity_minutes":30}'

{
  "success": true,
  "tool": "water-intake-calculator",
  "result": {
    "baseMl": 2450,
    "activityAdjustmentMl": 360,
    "totalMl": 2810,
    "totalLiters": 2.81
  }
}

Heart Rate Zones

Estimate maximum heart rate and 5 training heart-rate zones from age, using the "220 minus age" formula (default) or the Tanaka formula (208 - 0.7 x age), expressed either as percent of max heart rate (default) or, given a resting heart rate, the Karvonen percent-of-heart-rate-reserve method. Informational estimate only, not medical advice — max heart rate has a wide individual error margin; consult a healthcare professional before starting an intense exercise program.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/heart-rate-zones \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"age":30,"formula":"max-hr","maxHrFormula":"220-age"}'

{
  "success": true,
  "tool": "heart-rate-zones",
  "result": {
    "age": 30,
    "maxHrFormula": "220-age",
    "maxHR": 190,
    "formula": "max-hr",
    "zones": [
      {
        "zone": 1,
        "label": "Warm up",
        "bpmMin": 95,
        "bpmMax": 114
      },
      {
        "zone": 2,
        "label": "Fat burn",
        "bpmMin": 114,
        "bpmMax": 133
      },
      {
        "zone": 3,
        "label": "Cardio",
        "bpmMin": 133,
        "bpmMax": 152
      },
      {
        "zone": 4,
        "label": "Hard",
        "bpmMin": 152,
        "bpmMax": 171
      },
      {
        "zone": 5,
        "label": "Max effort",
        "bpmMin": 171,
        "bpmMax": 190
      }
    ]
  }
}

Ideal Weight Calculator

Estimate "ideal" body weight from height using four classic reference formulas (Devine, Robinson, Miller, Hamwi), originally developed for clinical drug-dosing reference rather than a personal fitness target. Informational estimate only, not medical advice — a healthy weight range depends on many individual factors beyond height.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ideal-weight-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"sex":"male","height_cm":175}'

{
  "success": true,
  "tool": "ideal-weight-calculator",
  "result": {
    "heightIn": 68.9,
    "devineKg": 70.5,
    "robinsonKg": 68.9,
    "millerKg": 68.7,
    "hamwiKg": 72.3,
    "averageKg": 70.1
  }
}

Pregnancy Due Date Calculator

Estimate a pregnancy due date and current gestational age from the first day of the last menstrual period (LMP) using Naegele's rule (LMP + 280 days), optionally adjusted for a cycle length other than 28 days. Informational estimate only, not medical advice — actual due dates vary; consult your doctor or midwife for personalized prenatal care.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pregnancy-due-date-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"lmp":"2026-01-01"}'

{
  "success": true,
  "tool": "pregnancy-due-date-calculator",
  "result": {
    "lmp": "2026-01-01",
    "cycleLength": 28,
    "dueDate": "2026-10-08",
    "today": "2026-01-01",
    "gestationalAgeWeeks": 0,
    "gestationalAgeDays": 0
  }
}

Calorie Calculator

Estimate daily calorie targets to maintain, lose, or gain weight, based on TDEE (Mifflin-St Jeor BMR x activity factor) and a calorie deficit/surplus amount (default 500 kcal/day, a common rule-of-thumb for roughly 0.45kg/1lb of weight change per week). Informational estimate only, not medical or nutrition advice — consult a qualified professional before starting a weight-management plan.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/calorie-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":80,"height_cm":180,"age":30,"sex":"male","activity":"moderate","adjustment":500}'

{
  "success": true,
  "tool": "calorie-calculator",
  "result": {
    "tdee": 2759,
    "maintain": 2759,
    "lose": 2259,
    "gain": 3259,
    "adjustment": 500
  }
}

Macro Calculator

Split a daily calorie target into protein, carbohydrate, and fat grams using a percentage split (default 30% protein / 40% carbs / 30% fat) or a named goal preset, at 4 kcal/g for protein and carbs and 9 kcal/g for fat. Informational estimate only, not medical or nutrition advice.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/macro-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"calories":2000,"protein_pct":30,"carbs_pct":40,"fat_pct":30}'

{
  "success": true,
  "tool": "macro-calculator",
  "result": {
    "calories": 2000,
    "proteinPct": 30,
    "carbsPct": 40,
    "fatPct": 30,
    "proteinG": 150,
    "carbsG": 200,
    "fatG": 66.7
  }
}

TDEE Calculator

Estimate Total Daily Energy Expenditure (TDEE) — Mifflin-St Jeor BMR multiplied by an activity factor. Informational estimate only, not medical or nutrition advice — consult a qualified professional for a personalized plan.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/tdee-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":80,"height_cm":180,"age":30,"sex":"male","activity":"moderate"}'

{
  "success": true,
  "tool": "tdee-calculator",
  "result": {
    "bmr": 1780,
    "activity": "moderate",
    "activityFactor": 1.55,
    "tdee": 2759
  }
}

One Rep Max Calculator

Estimate one-rep max (1RM) from a weight lifted for multiple reps, using the Epley formula (weight x (1 + reps/30)) and the Brzycki formula (weight x 36/(37 - reps); undefined at 37+ reps), plus an approximate percentage-of-1RM training table. Informational estimate only, not medical advice — actual one-rep max varies by exercise, fatigue, and technique.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/one-rep-max-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight":100,"reps":5,"unit":"kg"}'

{
  "success": true,
  "tool": "one-rep-max-calculator",
  "result": {
    "weight": 100,
    "reps": 5,
    "unit": "kg",
    "epley": 116.67,
    "brzycki": 112.5,
    "average": 114.58,
    "percentTable": [
      {
        "percent": 100,
        "reps": 1,
        "weight": 114.6
      },
      {
        "percent": 95,
        "reps": 2,
        "weight": 108.9
      },
      {
        "percent": 90,
        "reps": 4,
        "weight": 103.1
      },
      {
        "percent": 85,
        "reps": 6,
        "weight": 97.4
      },
      {
        "percent": 80,
        "reps": 8,
        "weight": 91.7
      },
      {
        "percent": 75,
        "reps": 10,
        "weight": 85.9
      },
      {
        "percent": 70,
        "reps": 12,
        "weight": 80.2
      },
      {
        "percent": 65,
        "reps": 15,
        "weight": 74.5
      },
      {
        "percent": 60,
        "reps": 20,
        "weight": 68.7
      },
      {
        "percent": 55,
        "reps": 24,
        "weight": 63
      },
      {
        "percent": 50,
        "reps": 30,
        "weight": 57.3
      }
    ]
  }
}

Pace Calculator

Solve for pace, time, or distance given the other two (pace = time / distance), for running, walking, or cycling splits. Accepts time and pace as a plain number of seconds, "MM:SS", or "HH:MM:SS". Informational estimate only, not medical advice.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/pace-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"solve":"pace","distance":10,"time":"50:00","distanceUnit":"km"}'

{
  "success": true,
  "tool": "pace-calculator",
  "result": {
    "solve": "pace",
    "distanceUnit": "km",
    "distance": 10,
    "timeSeconds": 3000,
    "time": "50:00",
    "paceSecondsPerUnit": 300,
    "pace": "5:00/km"
  }
}

Calories Burned Calculator

Estimate calories burned during an activity using MET (Metabolic Equivalent of Task) values from the widely-cited Compendium of Physical Activities (Ainsworth et al., 2011): kcal = MET x 3.5 x weight(kg) / 200 x minutes. Informational estimate only, not medical advice — actual energy expenditure varies by individual fitness, terrain, and effort.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/calories-burned-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"activity":"running-6mph","weight_kg":70,"minutes":30}'

{
  "success": true,
  "tool": "calories-burned-calculator",
  "result": {
    "activity": "running-6mph",
    "met": 9.8,
    "weightKg": 70,
    "minutes": 30,
    "kcal": 360.2
  }
}

Protein Intake Calculator

Estimate daily protein intake (grams) from body weight and activity level, using general grams-per-kilogram guidelines (0.8 g/kg sedentary up to 2.2 g/kg for athletes/heavy strength training). Informational estimate only, not medical or nutrition advice — individual protein needs vary.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/protein-intake-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"weight_kg":70,"activity":"active"}'

{
  "success": true,
  "tool": "protein-intake-calculator",
  "result": {
    "weightKg": 70,
    "activity": "active",
    "gramsPerKg": 1.6,
    "proteinGramsPerDay": 112
  }
}

Sleep Calculator

List bedtimes or wake times aligned to full 90-minute sleep cycles (plus ~14 minutes to fall asleep), given either a wake-up time ("wake-to-bed") or a bedtime ("bed-to-wake"). Informational estimate only, not medical advice — individual sleep-cycle length varies; consult a doctor about a persistent sleep problem.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/sleep-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"wake-to-bed","time":"07:00"}'

{
  "success": true,
  "tool": "sleep-calculator",
  "result": {
    "mode": "wake-to-bed",
    "time": "07:00",
    "options": [
      {
        "cycles": 6,
        "hours": 9,
        "time": "21:46"
      },
      {
        "cycles": 5,
        "hours": 7.5,
        "time": "23:16"
      },
      {
        "cycles": 4,
        "hours": 6,
        "time": "00:46"
      },
      {
        "cycles": 3,
        "hours": 4.5,
        "time": "02:16"
      }
    ]
  }
}

BAC Calculator

Estimate blood alcohol concentration (BAC%) using the Widmark formula: BAC% = (grams of alcohol / (body weight in grams x distribution ratio)) x 100, minus 0.015% per hour elapsed. Distribution ratio r = 0.68 for men, 0.55 for women; each standard drink is treated as ~14g of pure ethanol. THIS IS AN ESTIMATE ONLY — not medical advice, and never a substitute for a breathalyzer or blood test. Individual alcohol metabolism varies widely by body composition, food intake, medication, and other factors — never use it to decide whether it is safe to drive. If you have been drinking, do not drive; use a designated driver, taxi, or rideshare instead.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bac-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"drinks":3,"weight_kg":80,"hours":2,"sex":"male"}'

{
  "success": true,
  "tool": "bac-calculator",
  "result": {
    "drinks": 3,
    "weightKg": 80,
    "hours": 2,
    "sex": "male",
    "bacPercent": 0.047,
    "overLegalLimitUS": false,
    "note": "Estimate only — never use this to decide whether it is safe to drive. If you have been drinking, do not drive."
  }
}

Ovulation Calculator

Estimate ovulation date, fertile window, and next expected period from the first day of the last menstrual period (LMP) and average cycle length, using ovulation = LMP + (cycle length - 14) days and a fertile window from 5 days before ovulation through ovulation day. Informational estimate only, not medical advice — actual ovulation timing varies; consult your doctor for personalized guidance.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ovulation-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"lmp":"2026-01-01","cycleLength":28}'

{
  "success": true,
  "tool": "ovulation-calculator",
  "result": {
    "lmp": "2026-01-01",
    "cycleLength": 28,
    "ovulationDate": "2026-01-15",
    "fertileWindowStart": "2026-01-10",
    "fertileWindowEnd": "2026-01-15",
    "nextPeriodDate": "2026-01-29"
  }
}

Body Type Calculator

Estimate a rough body-frame/somatotype leaning (ectomorph/mesomorph/endomorph) from a height-to-wrist-circumference ratio. This is an APPROXIMATION based on an informal frame-size heuristic, NOT a clinical Heath-Carter somatotype assessment — informational only, not medical advice.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/body-type-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"sex":"male","height_cm":175,"wrist_cm":16}'

{
  "success": true,
  "tool": "body-type-calculator",
  "result": {
    "heightToWristRatio": 10.94,
    "frameSize": "small",
    "somatotype": "ectomorph-leaning",
    "note": "Approximation only, not a clinical somatotype assessment."
  }
}

Loan Calculator

Calculate the monthly payment, total interest, and total amount paid on a fixed-rate amortizing loan.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/loan-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"principal":200000,"annualRate":6,"years":30}'

{
  "success": true,
  "tool": "loan-calculator",
  "result": {
    "monthlyPayment": 1199.1,
    "totalInterest": 231676.38,
    "totalPaid": 431676.38
  }
}

Compound Interest Calculator

Calculate the final amount and interest earned on a principal under compound interest.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/compound-interest-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"principal":10000,"rate":5,"years":10,"compoundsPerYear":12}'

{
  "success": true,
  "tool": "compound-interest-calculator",
  "result": {
    "finalAmount": 16470.09,
    "interestEarned": 6470.09
  }
}

VAT Calculator

Calculate VAT (value-added tax) either way: `mode: "add"` treats `amount` as the net (pre-VAT) price and adds VAT on top; `mode: "remove"` treats `amount` as the gross (VAT-inclusive) price and extracts the VAT already included in it.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/vat-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"amount":100,"vatRate":20,"mode":"add"}'

{
  "success": true,
  "tool": "vat-calculator",
  "result": {
    "net": 100,
    "vat": 20,
    "gross": 120
  }
}

Salary Converter

Convert a salary/wage between pay periods (hourly, daily, weekly, monthly, annual), given the standard hours-per-week and weeks-per-year used to bridge hourly/daily figures to the rest.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/salary-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"amount":50000,"fromPeriod":"annual","toPeriod":"hourly","hoursPerWeek":40,"weeksPerYear":52}'

{
  "success": true,
  "tool": "salary-converter",
  "result": {
    "convertedValue": 24.04,
    "breakdown": {
      "hourly": 24.04,
      "daily": 192.31,
      "weekly": 961.54,
      "monthly": 4166.67,
      "annual": 50000
    }
  }
}

Bill Splitter

Split a restaurant/group bill (with tip) evenly across a number of people.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bill-splitter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"billAmount":100,"numPeople":4,"tipPercent":15}'

{
  "success": true,
  "tool": "bill-splitter",
  "result": {
    "perPerson": 28.75,
    "totalWithTip": 115,
    "tipAmount": 15
  }
}

Margin Calculator

Calculate profit margin and markup from a cost and a selling price. Accepts the selling price as either `revenue` or `price` (aliases for the same value) — provide one of them.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/margin-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"cost":50,"revenue":80}'

{
  "success": true,
  "tool": "margin-calculator",
  "result": {
    "profit": 30,
    "margin": 37.5,
    "markup": 60
  }
}

Mortgage Calculator

Calculate the monthly mortgage payment for a home purchase, broken down into principal & interest, property tax, and insurance, given an optional down payment.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/mortgage-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"homePrice":400000,"downPayment":80000,"annualRate":6.5,"years":30,"propertyTax":4800,"insurance":1200}'

{
  "success": true,
  "tool": "mortgage-calculator",
  "result": {
    "loanAmount": 320000,
    "monthlyPrincipalAndInterest": 2022.62,
    "monthlyTax": 400,
    "monthlyInsurance": 100,
    "monthlyPayment": 2522.62,
    "totalInterest": 408142.36,
    "totalPaid": 908142.36
  }
}

Investment Return Calculator

Project the future value of an initial investment plus fixed monthly contributions under a constant annual return.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/investment-return-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"initial":10000,"monthlyContribution":500,"rate":7,"years":20}'

{
  "success": true,
  "tool": "investment-return-calculator",
  "result": {
    "finalValue": 300850.72,
    "totalContributed": 130000,
    "totalGain": 170850.72
  }
}

Currency Converter

Convert an amount between currencies using static, approximate exchange rates baked into this tool — NOT a live/real-time rate feed. Rates are periodically-updated snapshots, not current market rates.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/currency-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"amount":100,"from":"USD","to":"EUR"}'

{
  "success": true,
  "tool": "currency-converter",
  "result": {
    "result": 92,
    "rate": 0.92,
    "note": "Approximate static rate, not live."
  }
}

Simple Interest Calculator

Calculate simple (non-compounding) interest on a principal over a period of time.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/simple-interest-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"principal":1000,"rate":5,"time":3}'

{
  "success": true,
  "tool": "simple-interest-calculator",
  "result": {
    "interest": 150,
    "total": 1150
  }
}

Retirement Calculator

Project a retirement savings balance from a current balance, a fixed monthly contribution, and an expected annual rate of return.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/retirement-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"currentAge":30,"retireAge":65,"currentSavings":20000,"monthlyContribution":500,"annualRate":7}'

{
  "success": true,
  "tool": "retirement-calculator",
  "result": {
    "monthsToRetirement": 420,
    "projectedBalance": 1130650.34
  }
}

Savings Goal Calculator

Project a savings goal, selected by `mode`: "months-to-goal" (given a fixed monthly contribution, how many months to reach the goal) or "required-monthly" (given a target number of months, the monthly contribution needed to reach the goal).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/savings-goal-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"mode":"months-to-goal","goal":50000,"currentSavings":5000,"monthlyContribution":500,"annualRate":6}'

{
  "success": true,
  "tool": "savings-goal-calculator",
  "result": {
    "monthsToGoal": 72
  }
}

Amortization Schedule Calculator

Build a full amortization schedule for a fixed-rate loan: per-period payment, principal paid, interest paid, and remaining balance. Bounded to 1200 total periods (years × paymentsPerYear).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/amortization-schedule-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"principal":10000,"annualRate":6,"years":1,"paymentsPerYear":12}'

{
  "success": true,
  "tool": "amortization-schedule-calculator",
  "result": {
    "monthlyPayment": 860.66,
    "totalInterest": 327.97,
    "totalPaid": 10327.97,
    "schedule": [
      {
        "period": 1,
        "payment": 860.66,
        "principalPaid": 810.66,
        "interestPaid": 50,
        "balance": 9189.34
      },
      {
        "period": 2,
        "payment": 860.66,
        "principalPaid": 814.72,
        "interestPaid": 45.95,
        "balance": 8374.62
      },
      {
        "period": 3,
        "payment": 860.66,
        "principalPaid": 818.79,
        "interestPaid": 41.87,
        "balance": 7555.83
      },
      {
        "period": 4,
        "payment": 860.66,
        "principalPaid": 822.89,
        "interestPaid": 37.78,
        "balance": 6732.94
      },
      {
        "period": 5,
        "payment": 860.66,
        "principalPaid": 827,
        "interestPaid": 33.66,
        "balance": 5905.94
      },
      {
        "period": 6,
        "payment": 860.66,
        "principalPaid": 831.13,
        "interestPaid": 29.53,
        "balance": 5074.81
      },
      {
        "period": 7,
        "payment": 860.66,
        "principalPaid": 835.29,
        "interestPaid": 25.37,
        "balance": 4239.52
      },
      {
        "period": 8,
        "payment": 860.66,
        "principalPaid": 839.47,
        "interestPaid": 21.2,
        "balance": 3400.05
      },
      {
        "period": 9,
        "payment": 860.66,
        "principalPaid": 843.66,
        "interestPaid": 17,
        "balance": 2556.39
      },
      {
        "period": 10,
        "payment": 860.66,
        "principalPaid": 847.88,
        "interestPaid": 12.78,
        "balance": 1708.5
      },
      {
        "period": 11,
        "payment": 860.66,
        "principalPaid": 852.12,
        "interestPaid": 8.54,
        "balance": 856.38
      },
      {
        "period": 12,
        "payment": 860.66,
        "principalPaid": 856.38,
        "interestPaid": 4.28,
        "balance": 0
      }
    ]
  }
}

ROI Calculator

Calculate return on investment (ROI) from an initial investment and a final value. When `years` is provided, also returns the annualized ROI (CAGR).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/roi-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"initialInvestment":10000,"finalValue":15000,"years":5}'

{
  "success": true,
  "tool": "roi-calculator",
  "result": {
    "roi": 50,
    "annualizedRoi": 8.4472
  }
}

Inflation Calculator

Calculate the inflation-adjusted future value of an amount, and how much purchasing power that amount loses over the given number of years at a constant annual inflation rate.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/inflation-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"amount":1000,"annualInflationRate":3,"years":10}'

{
  "success": true,
  "tool": "inflation-calculator",
  "result": {
    "adjustedValue": 1343.92,
    "purchasingPowerLoss": 255.91
  }
}

Credit Card Payoff Calculator

Simulate paying off a credit card balance at a fixed monthly payment: months to payoff and total interest paid.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/credit-card-payoff-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"balance":5000,"apr":19.99,"monthlyPayment":200}'

{
  "success": true,
  "tool": "credit-card-payoff-calculator",
  "result": {
    "monthsToPayoff": 33,
    "totalInterest": 1521.02,
    "totalPaid": 6521.02
  }
}

Debt Payoff Calculator

Simulate paying off multiple debts with a shared monthly budget (every debt's minimum payment plus an optional extra amount), using the "avalanche" (highest APR paid off first) or "snowball" (smallest balance first) strategy. Every active debt's minimum is paid first each month; the leftover budget cascades to the top-priority debt. Up to 50 debts.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/debt-payoff-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"debts":"5000 22 150\n3000 15 90","extraPayment":200,"strategy":"avalanche"}'

{
  "success": true,
  "tool": "debt-payoff-calculator",
  "result": {
    "monthsToPayoff": 22,
    "totalInterest": 1460.56,
    "totalPaid": 9460.56,
    "debtCount": 2
  }
}

Sales Tax Calculator

Calculate sales tax on a pre-tax amount and the resulting total.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/sales-tax-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"amount":250,"taxRate":8.875}'

{
  "success": true,
  "tool": "sales-tax-calculator",
  "result": {
    "tax": 22.19,
    "total": 272.19
  }
}

Depreciation Calculator

Build a yearly depreciation schedule for an asset using the "straight-line" or "declining-balance" (double-declining, floored at the salvage value) method. Bounded to 100 years.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/depreciation-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"assetCost":50000,"salvageValue":5000,"usefulLifeYears":5,"method":"straight-line"}'

{
  "success": true,
  "tool": "depreciation-calculator",
  "result": {
    "method": "straight-line",
    "schedule": [
      {
        "year": 1,
        "depreciation": 9000,
        "bookValue": 41000
      },
      {
        "year": 2,
        "depreciation": 9000,
        "bookValue": 32000
      },
      {
        "year": 3,
        "depreciation": 9000,
        "bookValue": 23000
      },
      {
        "year": 4,
        "depreciation": 9000,
        "bookValue": 14000
      },
      {
        "year": 5,
        "depreciation": 9000,
        "bookValue": 5000
      }
    ],
    "totalDepreciation": 45000,
    "finalBookValue": 5000
  }
}

Commission Calculator

Calculate sales commission from a sale amount and commission rate, with an optional base salary added on top.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/commission-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"saleAmount":20000,"commissionRate":5,"baseSalary":3000}'

{
  "success": true,
  "tool": "commission-calculator",
  "result": {
    "commission": 1000,
    "total": 4000
  }
}

Break-Even Calculator

Calculate the break-even point (units and revenue) given fixed costs, price per unit, and variable cost per unit.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/break-even-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"fixedCosts":10000,"pricePerUnit":50,"variableCostPerUnit":20}'

{
  "success": true,
  "tool": "break-even-calculator",
  "result": {
    "breakEvenUnits": 334,
    "breakEvenRevenue": 16700
  }
}

Rent vs Buy Calculator

Compare the total cost of renting vs. buying a home over a number of years: monthly rent (with an optional annual increase) vs. a 30-year mortgage payment plus down payment, net of home equity built from paydown and appreciation. Assumes a fixed 30-year mortgage term regardless of the comparison horizon.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/rent-vs-buy-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"monthlyRent":2000,"homePrice":350000,"downPayment":70000,"mortgageRate":6.5,"years":10,"appreciationRate":3,"rentIncreaseRate":3}'

{
  "success": true,
  "tool": "rent-vs-buy-calculator",
  "result": {
    "monthlyMortgagePayment": 1769.79,
    "totalRentCost": 275133.1,
    "totalBuyCost": 49377.28,
    "homeEquity": 232997.58,
    "recommendation": "buy"
  }
}

What Is My IP

Report the caller IP address (supplied in "ip" — the site's own tool page and the metered API route both fill this in from the actual request's forwarded-for header before calling this endpoint) plus browser/OS/device details parsed from an optional User-Agent string. Does NOT perform IP geolocation — no city, region, or ISP lookup is included, only what the request itself reveals.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/what-is-my-ip \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"ip":"203.0.113.42","userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"}'

{
  "success": true,
  "tool": "what-is-my-ip",
  "result": {
    "ip": "203.0.113.42",
    "ipVersion": 4,
    "isPrivate": false,
    "browser": {
      "name": "Chrome",
      "version": "120.0.0.0"
    },
    "os": {
      "name": "Windows",
      "version": "10"
    },
    "device": {}
  }
}

DNS Lookup

Look up DNS records for a domain — A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, or "ALL" of them — via node:dns. This RESOLVES the domain (a DNS query) but never connects to any address the records return, so it carries none of the SSRF risk the URL/host-based network tools do.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/dns-lookup \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"domain":"example.com","type":"A"}'

{
  "success": true,
  "tool": "dns-lookup",
  "result": {
    "domain": "example.com",
    "type": "A",
    "records": {
      "A": [
        "93.184.216.34"
      ]
    }
  }
}

Website Status Checker

Check whether a website is up — status code, response time, and the final URL after redirects — via an SSRF-guarded GET request. A site that is down, unreachable, or too slow is the tool's normal answer (`up: false`), not an error; a request refused because it targets a private/internal/loopback address IS an error, since that is a blocked request rather than an observation about the target site.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/website-status-checker \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com"}'

{
  "success": true,
  "tool": "website-status-checker",
  "result": {
    "up": true,
    "statusCode": 200,
    "statusText": "OK",
    "responseTimeMs": 123,
    "finalUrl": "https://example.com/",
    "server": "ECS (nyb/1D2A)",
    "contentType": "text/html; charset=UTF-8"
  }
}

HTTP Headers Viewer

View the HTTP response headers for a URL via an SSRF-guarded GET request, plus a security-header summary (present/absent for HSTS, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy, and Permissions-Policy).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/http-headers-viewer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com"}'

{
  "success": true,
  "tool": "http-headers-viewer",
  "result": {
    "statusCode": 200,
    "finalUrl": "https://example.com/",
    "headers": {
      "content-type": "text/html; charset=UTF-8",
      "server": "ECS (nyb/1D2A)"
    },
    "securityHeaders": {
      "Strict-Transport-Security (HSTS)": {
        "present": false,
        "value": null
      },
      "Content-Security-Policy": {
        "present": false,
        "value": null
      },
      "X-Frame-Options": {
        "present": false,
        "value": null
      },
      "X-Content-Type-Options": {
        "present": false,
        "value": null
      },
      "Referrer-Policy": {
        "present": false,
        "value": null
      },
      "Permissions-Policy": {
        "present": false,
        "value": null
      }
    }
  }
}

User Agent Parser

Parse a User-Agent string into browser, rendering engine, operating system, device, and CPU details, using the ua-parser-js library (a maintained signature database matched against real-world User-Agent strings) rather than ad hoc regular expressions.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/user-agent-parser \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"userAgent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"}'

{
  "success": true,
  "tool": "user-agent-parser",
  "result": {
    "browser": {
      "name": "Chrome",
      "version": "120.0.0.0"
    },
    "engine": {
      "name": "Blink",
      "version": "120.0.0.0"
    },
    "os": {
      "name": "Windows",
      "version": "10"
    },
    "device": {},
    "cpu": {
      "architecture": "amd64"
    }
  }
}

WHOIS Lookup

Look up domain registration details (registrar, creation/update/expiry dates, name servers, status codes) via a hand-rolled TCP-43 WHOIS client: query whois.iana.org for the TLD's referral server, then query that server for the domain. WHOIS is a free-text protocol with no universal schema, so parsed-field completeness varies by registry — the raw response text is always included alongside the best-effort parsed fields.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/whois-lookup \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"domain":"example.com"}'

{
  "success": true,
  "tool": "whois-lookup",
  "result": {
    "domain": "example.com",
    "whoisServer": "whois.verisign-grs.com",
    "raw": "Domain Name: EXAMPLE.COM\n...",
    "parsed": {
      "registrar": "RESERVED-Internet Assigned Numbers Authority",
      "createdDate": "1995-08-14T04:00:00Z",
      "updatedDate": "2026-01-16T18:26:50Z",
      "expiresDate": "2026-08-13T04:00:00Z",
      "nameServers": [
        "A.IANA-SERVERS.NET",
        "B.IANA-SERVERS.NET"
      ],
      "status": [
        "clientDeleteProhibited"
      ]
    }
  }
}

SSL Certificate Checker

Inspect the SSL/TLS certificate a host presents — subject, issuer, validity window, days until expiry, subject alternative names, serial number, signature algorithm, and chain length — via an SSRF-guarded TLS connection. The connection deliberately does not validate trust (an expired, self-signed, or hostname- mismatched certificate is exactly what this tool is for reporting on).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ssl-certificate-checker \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"host":"example.com"}'

{
  "success": true,
  "tool": "ssl-certificate-checker",
  "result": {
    "subject": {
      "CN": "example.com"
    },
    "issuer": {
      "C": "US",
      "O": "SSL Corporation",
      "CN": "Cloudflare TLS Issuing ECC CA 3"
    },
    "validFrom": "May 31 21:39:12 2026 GMT",
    "validTo": "Aug 29 21:41:26 2026 GMT",
    "daysUntilExpiry": 43,
    "san": [
      "DNS:example.com",
      "DNS:*.example.com"
    ],
    "serialNumber": "1AA73FEA257BE3334B9A29552E6F878E",
    "signatureAlgorithm": "ecdsa-with-SHA256",
    "isExpired": false,
    "isValidNow": true,
    "chainLength": 1
  }
}

IP Subnet Calculator

Calculate IPv4 subnet details — network address, broadcast address, usable host range, host counts, and wildcard/subnet mask — from a CIDR block (e.g. "192.168.1.0/24") or an IP + subnet mask pair. Handles the /31 (RFC 3021 point-to-point, 0 usable hosts by the classic count) and /32 (single host) edge cases.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/ip-subnet-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"cidr":"192.168.1.0/24"}'

{
  "success": true,
  "tool": "ip-subnet-calculator",
  "result": {
    "cidr": "192.168.1.0/24",
    "network": "192.168.1.0",
    "broadcast": "192.168.1.255",
    "firstHost": "192.168.1.1",
    "lastHost": "192.168.1.254",
    "usableHosts": 254,
    "totalHosts": 256,
    "wildcardMask": "0.0.0.255",
    "subnetMask": "255.255.255.0",
    "prefixLength": 24,
    "ipClass": "C"
  }
}

Bandwidth Calculator

Calculate file transfer time from a file size and a link speed. Uses a DECIMAL (1000-based) convention throughout: 1 KB/MB/GB/TB = 1000^n bytes, 1 Kbps/Mbps/Gbps = 1000^n bits/second, 8 bits = 1 byte — the same convention ISPs use to advertise speed, stated explicitly in every response (`convention` field) since a 1024-based (binary) reading of the same units gives a different number.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/bandwidth-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"fileSize":1,"fileSizeUnit":"GB","speed":100,"speedUnit":"Mbps"}'

{
  "success": true,
  "tool": "bandwidth-calculator",
  "result": {
    "fileSize": 1,
    "fileSizeUnit": "GB",
    "fileSizeBytes": 1000000000,
    "speed": 100,
    "speedUnit": "Mbps",
    "speedBitsPerSecond": 100000000,
    "transferSeconds": 80,
    "transferHuman": "1m 20s",
    "convention": "Decimal (1000-based) convention: 1 KB/MB/GB/TB = 1000^n bytes; 1 Kbps/Mbps/Gbps = 1000^n bits/second; 8 bits = 1 byte. Some operating systems display file size using 1024-based binary units instead (labeled \"GB\" but meaning GiB) — this tool always uses the decimal convention above."
  }
}

Website Speed Test

Measure page-load timing for a URL — TTFB, DOMContentLoaded, load, transferred bytes, request count, and a resource-type breakdown — via a real headless-Chrome navigation and the browser's own Navigation/Resource Timing APIs. This is lightweight navigation-timing, NOT a full Lighthouse audit (no performance score, no Core Web Vitals like LCP/CLS/INP). The target host is validated and pinned before Chrome ever launches — Chrome itself is locked to that one pinned IP via --host-resolver-rules, and every sub-resource request to any OTHER host is blocked outright, so the page cannot pivot this server's network position elsewhere.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/website-speed-test \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"url":"https://example.com"}'

{
  "success": true,
  "tool": "website-speed-test",
  "result": {
    "url": "https://example.com",
    "finalUrl": "https://example.com/",
    "ttfbMs": 88,
    "domContentLoadedMs": 210,
    "loadMs": 245,
    "transferredBytes": 1534,
    "requestCount": 1,
    "resourceBreakdown": {
      "script": 0,
      "css": 0,
      "image": 0,
      "font": 0,
      "other": 0
    }
  }
}

World Clock

Show the local time in up to 50 IANA timezones for a given instant (default: now). DST-aware via Intl.DateTimeFormat — each zone's offset is looked up for that specific instant.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/world-clock \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"at":"2026-06-01T12:00:00Z","zones":"UTC,America/New_York,Asia/Kolkata"}'

{
  "success": true,
  "tool": "world-clock",
  "result": {
    "at": "2026-06-01T12:00:00.000Z",
    "zones": [
      {
        "zone": "UTC",
        "offset": "+00:00",
        "localTime": "2026-06-01T12:00:00"
      },
      {
        "zone": "America/New_York",
        "offset": "-04:00",
        "localTime": "2026-06-01T08:00:00"
      },
      {
        "zone": "Asia/Kolkata",
        "offset": "+05:30",
        "localTime": "2026-06-01T17:30:00"
      }
    ]
  }
}

Timezone Converter

Convert a wall-clock date and time from one IANA timezone to another. DST-aware via the built-in Intl.DateTimeFormat — the UTC offset for each zone is looked up for the specific instant being converted, never hardcoded, so results are correct on both sides of a Daylight Saving Time transition.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/timezone-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"datetime":"2026-06-01T12:00","fromZone":"America/New_York","toZone":"Europe/London"}'

{
  "success": true,
  "tool": "timezone-converter",
  "result": {
    "datetime": "2026-06-01T12:00",
    "fromZone": "America/New_York",
    "toZone": "Europe/London",
    "fromOffset": "-04:00",
    "toOffset": "+01:00",
    "utc": "2026-06-01T16:00:00.000Z",
    "convertedDatetime": "2026-06-01T17:00:00"
  }
}

Week Number Calculator

Calculate the ISO-8601 week number and ISO week-year for a date. ISO weeks start Monday and a week belongs to the year containing its Thursday, so Jan 1-3 can fall in the PRIOR year's final week (e.g. W52/W53), and some years have a 53rd week.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/week-number-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"date":"2026-01-01"}'

{
  "success": true,
  "tool": "week-number-calculator",
  "result": {
    "date": "2026-01-01",
    "isoYear": 2026,
    "isoWeek": 1,
    "isoWeekString": "2026-W01"
  }
}

Day of Week Calculator

Get the weekday name for a date, plus its day-of-year and whether that year is a leap year. Pure UTC calendar math (Date.UTC/getUTCDay) — no local-timezone off-by-one.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/day-of-week-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"date":"2026-07-17"}'

{
  "success": true,
  "tool": "day-of-week-calculator",
  "result": {
    "date": "2026-07-17",
    "weekday": "Friday",
    "weekdayIndex": 5,
    "dayOfYear": 198,
    "isLeapYear": false
  }
}

Countdown Timer

Compute the time remaining until a target instant, from a reference instant (default: now). If the target has already passed, returns the elapsed time with isPast:true instead of erroring.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/countdown-timer \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"target":"2026-01-02T12:30:00Z","from":"2026-01-01T00:00:00Z"}'

{
  "success": true,
  "tool": "countdown-timer",
  "result": {
    "target": "2026-01-02T12:30:00.000Z",
    "from": "2026-01-01T00:00:00.000Z",
    "isPast": false,
    "days": 1,
    "hours": 12,
    "minutes": 30,
    "seconds": 0,
    "totalSeconds": 131400
  }
}

Hours Calculator

Calculate hours worked between a start and end clock time, minus an optional unpaid break, as decimal hours and "H:MM". If "end" is earlier than "start" the shift is treated as crossing midnight (24 hours are added to "end") rather than as an error.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/hours-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"start":"09:00","end":"17:30","break":"0:30"}'

{
  "success": true,
  "tool": "hours-calculator",
  "result": {
    "start": "09:00",
    "end": "17:30",
    "breakMinutes": 30,
    "overnight": false,
    "workedMinutes": 480,
    "decimalHours": 8,
    "hhmm": "8:00"
  }
}

Time Duration Calculator

Compute the duration between two ISO instants, broken into days/hours/minutes/seconds plus running totals in each unit. "end" must not be before "start".

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/time-duration-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"start":"2026-01-01T00:00:00Z","end":"2026-01-02T12:30:00Z"}'

{
  "success": true,
  "tool": "time-duration-calculator",
  "result": {
    "start": "2026-01-01T00:00:00.000Z",
    "end": "2026-01-02T12:30:00.000Z",
    "days": 1,
    "hours": 12,
    "minutes": 30,
    "seconds": 0,
    "totalSeconds": 131400,
    "totalMinutes": 2190,
    "totalHours": 36.5,
    "totalDays": 1.52
  }
}

Age on Date Calculator

Calculate calendar-correct age (years, months, days) at a reference date, given a birthdate. Handles leap-day (Feb 29) birthdays: in a non-leap reference year, the anniversary is reached the day after Feb 28.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/age-on-date-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"birthdate":"1990-06-15","on":"2026-07-17"}'

{
  "success": true,
  "tool": "age-on-date-calculator",
  "result": {
    "birthdate": "1990-06-15",
    "on": "2026-07-17",
    "years": 36,
    "months": 1,
    "days": 2
  }
}

Date Pattern Calculator

Date arithmetic from a start date: either "shift" mode adds/subtracts an interval (amount + unit: days/weeks/months/years — month/year shifts clamp the day-of-month if the target month is shorter, e.g. Jan 31 + 1 month -> Feb 28), or "next-weekday" mode lists the next N (1-1000) occurrences of a weekday strictly after the start date. UTC-safe throughout.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/date-pattern-calculator \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"date":"2026-07-17","mode":"shift","operation":"add","amount":30,"unit":"days"}'

{
  "success": true,
  "tool": "date-pattern-calculator",
  "result": {
    "date": "2026-07-17",
    "mode": "shift",
    "operation": "add",
    "amount": 30,
    "unit": "days",
    "result": "2026-08-16"
  }
}

Length Converter

Convert a length/distance value between metric and imperial/nautical units. Units: mm, cm, m, km, in, ft, yd, mi, nautical-mile (base unit: meters).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/length-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":100,"from":"km","to":"mi"}'

{
  "success": true,
  "tool": "length-converter",
  "result": {
    "result": 62.13711922373339,
    "from": "km",
    "to": "mi",
    "allUnits": {
      "mm": 100000000,
      "cm": 10000000,
      "m": 100000,
      "km": 100,
      "in": 3937007.874015748,
      "ft": 328083.9895013123,
      "yd": 109361.32983377078,
      "mi": 62.13711922373339,
      "nautical-mile": 53.99568034557235
    }
  }
}

Weight Converter

Convert a weight/mass value between metric and imperial units. Units: mg, g, kg, tonne, oz, lb, stone (base unit: kilograms).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/weight-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":1,"from":"lb","to":"kg"}'

{
  "success": true,
  "tool": "weight-converter",
  "result": {
    "result": 0.45359237,
    "from": "lb",
    "to": "kg",
    "allUnits": {
      "mg": 453592.37000000005,
      "g": 453.59237,
      "kg": 0.45359237,
      "tonne": 0.00045359237000000004,
      "oz": 16.000000014109585,
      "lb": 1,
      "stone": 0.07142857142857142
    }
  }
}

Temperature Converter

Convert a temperature between Celsius, Fahrenheit, Kelvin, and Rankine. Uses the real AFFINE formulas (additive offset + scale, not a pure factor) via a Celsius pivot, and rejects any value that is physically below absolute zero (-273.15°C / -459.67°F / 0 K / 0°R). Units: celsius, fahrenheit, kelvin, rankine.

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/temperature-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":100,"from":"celsius","to":"fahrenheit"}'

{
  "success": true,
  "tool": "temperature-converter",
  "result": {
    "result": 212,
    "from": "celsius",
    "to": "fahrenheit"
  }
}

Data Storage Converter

Convert a digital storage size between units, using the BINARY (1024-based, i.e. KiB/MiB/GiB/TiB) convention — NOT the decimal/1000-based convention some vendors use. 1 GB = 1024 MB here. Units: bit, byte, KB, MB, GB, TB (base unit: bytes).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/data-storage-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":1,"from":"GB","to":"MB"}'

{
  "success": true,
  "tool": "data-storage-converter",
  "result": {
    "result": 1024,
    "from": "GB",
    "to": "MB",
    "allUnits": {
      "bit": 8589934592,
      "byte": 1073741824,
      "KB": 1048576,
      "MB": 1024,
      "GB": 1,
      "TB": 0.0009765625
    }
  }
}

Area Converter

Convert an area value between metric and imperial units. Units: mm2, cm2, m2, hectare, km2, in2, ft2, acre, mi2 (base unit: square meters).

Parameters

Example

curl -X POST https://freeconvertingtools.com/api/v1/tools/area-converter \
  -H "Authorization: Bearer fct_your_key" \
  -H "Content-Type: application/json" \
  -d '{"value":1,"from":"acre","to":"m2"}'

{
  "success": true,
  "tool": "area-converter",
  "result": {
    "result": 4046.8564224,
    "from": "acre",
    "to": "m2",
    "allUnits": {
      "mm2": 4046856422.4000006,
      "cm2": 40468564.224,
      "m2": 4046.8564224,
      "hectare": 0.40468564224000003,
      "km2": 0.0040468564224,
      "in2": 6272640,
      "ft2": 43560,
      "acre": 1,
      "mi2": 0.0015625
    }
  }
}

Volume Converter

Convert a volume value between metric and US customary units. Units: ml, l, m3, tsp, tbsp, fl-oz-us, cup-us, pint-us, quart-us, gallon-us (base unit: liters).

Parameters